,1,2,*Advances in the Molecular Mechanism and Genetic Regulation of Grain-filling Rate in Rice
Sunlu Chen1,2,?, Chengfang Zhan1,?, Hong Jiang1,2, Linhan Li1,2, Hongsheng Zhang,1,2,*通讯作者: E-mail:hszhang@njau.edu.cn。
责任编辑: 白羽红
收稿日期:2020-09-14接受日期:2020-11-11网络出版日期:2021-01-01
| 基金资助: |
Corresponding authors: *E-mail:hszhang@njau.edu.cn。
Received:2020-09-14Accepted:2020-11-11Online:2021-01-01
摘要
水稻(Oryza sativa)的高产优质是我国粮食安全的重要保障, 也是育种家一直追求的目标。水稻籽粒灌浆速率(GFR)是一个重要而复杂的农艺性状, 直接影响籽粒充实度、粒重和米质。目前, 快速灌浆的优良水稻品种缺乏, 可供育种利用的相关优异基因资源有限, 已成为制约水稻产量和品质进一步提高的瓶颈。相对于水稻的其它农艺性状, GFR具有复杂的时空动态和环境可变性, 相关研究长期围绕灌浆过程的生理生化特性和栽培措施展开, 而分子机制和遗传调控研究启动较晚。该文以近年来国内外发现的水稻GFR相关基因为主线, 从糖类代谢和运输相关基因对GFR的影响、转录和翻译调控基因对GFR的调节、粒型和粒重等相关数量性状位点(QTL)对GFR的作用, 以及GFR相关QTL的分析和克隆4个方面, 对GFR分子机制与遗传调控进行综述; 并对GFR的研究策略特别是表型组学相关技术的应用前景进行展望, 以期推动该领域的基础研究和育种应用。
关键词：
Abstract
High yield and good quality of rice are important guarantees for food security in China, as well as the objective which breeders are pursuing. Grain-filling rate (GFR) is an important and complex agronomic trait in rice, directly affecting grain plumpness, weight, and quality. To date, elite rice germplasm with rapid GFR is rare, and valuable gene resources for breeding remain limited, which has become a bottleneck for further improvement of yield and quality in rice breeding. Comparing with other rice agronomic traits, GFR is highly complex for its spatio-temporal dynamics and environment- dependent variability, the research of which has long been concentrated on the physiological and biochemical characteristics and cultivation measure control of grain-filling period. The study on the molecular mechanism and genetic regulation of GFR has arisen relatively recently. Here, focusing on the GFR-related genes in rice identified recently, we reviewed the preliminarily known molecular mechanism and genetic regulation of GFR, including the influence of sugar metabolism and transport-related genes on GFR, the transcriptional and translational regulatory genes in GFR, the function of grain size and weight-related quantitative trait loci (QTLs) of GFR, and the analysis of GFR-related QTLs; we also discussed the future perspective of the research strategies for GFR, especially the application potential of phenomics-related technologies for GFR research, in order to promote the foundational research and application in rice breeding.
Keywords：
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引用本文
陈孙禄, 詹成芳, 蒋红, 李琳涵, 张红生. 水稻籽粒灌浆速率的分子机制与遗传调控研究进展. 植物学报, 2021, 56(1): 80-89 doi:10.11983/CBB20157
Chen Sunlu, Zhan Chengfang, Jiang Hong, Li Linhan, Zhang Hongsheng.
水稻(Oryza sativa)是我国最重要的粮食作物, 也是禾谷类植物分子生物学研究的模式物种。水稻经过开花、授粉和双受精之后, 子房发育为颖果, 随后进入籽粒灌浆(grain filling)时期。此时, 叶片等绿色组织光合作用产生和积累的同化物向颖果运输并转化, 最终颖果发育成为成熟籽粒。因此, 籽粒灌浆是稻米形成的关键阶段, 灌浆特性决定稻米的最终产量和品质。籽粒灌浆特性包括籽粒灌浆速率(grain-filling rate, GFR)、灌浆持续时间(grain-filling duration, GFD)以及与各种环境因子(温度、水分和氮肥等)的互作等(Jones et al., 1979; Jongkaewwattana and Geng, 2001; 施伟等, 2020)。其中, GFR一般定义为颖果日均积累的干重, 其直接影响籽粒的充实度、粒重和米质等, 是重要而复杂的农艺性状之一(Yang and Zhang, 2006, 2010; Liu et al., 2019)。GFR传统测量方法基于较长的时间窗口(天数), 而且耗时费力, 但最近X射线显微计算机断层扫描(computed tomography, CT)技术的运用有望实现水稻GFR的实时和精细测量(Hu et al., 2020b)。
目前, 我国多数水稻品种GFR较低, 快速灌浆的优良水稻种质比较缺乏, 可供育种利用的相关优异基因资源非常有限, 严重制约了水稻产量和品质的进一步提高(Yang et al., 2001; Yang and Zhang, 2010; Liu et al., 2019)。相对于水稻的其它农艺性状, GFR具有复杂的时空动态和环境可变性。研究人员长期围绕水稻籽粒灌浆过程的生理生化特性和栽培措施展开研究, 而分子机制和遗传调控相关研究启动较晚。尽管以GFR为直接研究性状及鉴定到的GFR调控基因相对较少, 但在水稻其它性状尤其是粒型性状研究中, 通过分析籽粒灌浆动态曲线发现一些基因可能与GFR有关。本文以近年来国内外发现的水稻GFR相关基因为主线(图1), 对已知的GFR分子机制和遗传调控研究进行综述, 并对研究策略进行展望, 希望能吸引更多研究者对GFR分子遗传学的兴趣和关注, 进一步推动该领域的基础研究和育种应用。
图1
新窗口打开|下载原图ZIP|生成PPT图1已报道的水稻籽粒灌浆速率相关基因
Figure 1The known genes related to grain-filling rate in rice
1 糖类代谢和运输相关基因对GFR的影响
1.1 糖代谢酶相关基因
水稻籽粒的主要内含物是淀粉, 因此糖类代谢和运输在籽粒灌浆过程中至关重要。目前, 在已报道的水稻GFR相关基因中, 相当一部分是糖类代谢酶相关基因。光合作用产生的蔗糖需要转化为己糖磷酸酯才能进入籽粒细胞, 细胞壁转化酶(cell-wall invertase, CIN)在此过程中发挥至关重要的作用。CIN作为一类定位于细胞壁的蔗糖酶, 可将质外体中的蔗糖催化水解为葡萄糖和果糖(Sturm and Tang, 1999)。Hirose等(2002)从水稻灌浆籽粒中克隆到1个CIN基因OsCIN1。该基因在灌浆早期高丰度表达, 可能在籽粒灌浆中发挥重要作用, 但其对GFR的影响未知。Wang等(2008)筛选到1个灌浆不完全突变体gif1 (grain incomplete filling 1), 其GFR降低。图位克隆结果表明, GIF1编码水稻CIN (OsCIN2), 在籽粒灌浆早期控制蔗糖在胚乳中的卸载。在长期驯化过程中, OsCIN2基因启动子明显受到人工选择, 使得栽培稻OsCIN2等位基因主要在胚珠脉管部位表达, 而普通野生稻(O. rufipogon) OsCIN2等位基因具有广泛的时空表达; 将后者导入栽培稻中, 会显著降低栽培稻的GFR (Wang et al., 2008)。进一步研究发现, OsCIN2主要在灌浆过程中发挥作用, 而OsCIN1酶活较低, 可能主要参与调控其它生物学过程(Wang et al., 2010)。通过研究另一个灌浆缺陷突变体gif2, 鉴定到腺苷二磷酸葡萄糖焦磷酸化酶(ADP-glucose pyrophosphorylase, AGPase)的大亚基基因OsAGPL2 (Wei et al., 2017)。AGPase是淀粉合成的限速酶, 催化1-磷酸葡萄糖与ATP反应生成腺苷二磷酸葡萄糖(淀粉合成的前体), 其突变会影响籽粒中淀粉的合成, 导致GFR降低(Wei et al., 2017)。FLO6 (FLOURY ENDOSPERM 6)编码参与淀粉合成的含有C末端糖结合域48的蛋白CBM48, 该蛋白定位于质体上, 其C端与淀粉结合, 而N端与异淀粉酶1 (isoamylase1, ISA1)结合, 介导ISA1对淀粉的结合(ISA1无法直接与淀粉结合); 其可能是ISA1的底物识别亚基, FLO6突变导致GFR降低(Peng et al., 2014a)。最近的研究表明, 多个水稻糖酵解途径相关酶基因与GFR相关, 而糖酵解可以促进淀粉合成和代谢。OsPFP1编码糖酵解途径中的焦磷酸:果糖-6-磷酸1-磷酸转移酶(pyrophosphate:fructose-6-phosphate 1-phosphotransferase, PFP)的β亚基, 与3个α亚基共同形成异源四聚体, 催化果糖-6-磷酸与果糖-1,6-二磷酸间的可逆反应, 其突变导致籽粒造粉体和淀粉颗粒发育异常, 淀粉含量和GFR降低(Duan et al., 2016a; Chen et al., 2020)。丙酮酸激酶(pyruvate kinase, PK)催化糖酵解途径的最后一步反应, 即磷酸烯醇式丙酮酸和ADP转化生成丙酮酸和ATP, 是糖酵解途径的重要限速酶之一。OsPK2编码1个位于质体的PK (PKpα1), 与其它3个质体同工酶PKpα2、PKpβ1和PKpβ2形成异源复合体, 其突变导致籽粒淀粉合成异常, 复合淀粉颗粒显著减少, GFR降低(Cai et al., 2018)。OsPK3编码1个位于线粒体的PK, 其突变导致灌浆中后期GFR下降; OsPK3可以招募另外2个同功酶OsPK1和OsPK4, 分别形成2种不同的异二聚体, 在籽粒不同灌浆阶段发挥作用(Hu et al., 2020a)。OsPK3还在叶片中高表达, 特别是叶肉细胞和韧皮部伴胞中, 而ospk3突变体的叶片中会发生蔗糖和淀粉积累, 说明OsPK3还影响蔗糖从源到库的转运和卸载(Hu et al., 2020a)。上述糖类代谢酶相关基因均参与GFR的正调控, 其突变可导致GFR降低, 籽粒灌浆异常。
1.2 糖转运蛋白基因
蔗糖转运蛋白(sucrose transporter, SUT)基因是最早被发现与水稻籽粒灌浆相关的糖转运蛋白基因, 在水稻中有5个同源基因(Ishimaru et al., 2001; Aoki et al., 2003)。其中, OsSUT1主要在灌浆颖果的糊粉层表达, 抑制该基因的表达导致严重的灌浆缺陷, 表明GFR可能降低, 但是叶片的光合作用不受影响, 其可能负责将蔗糖从叶片质外体转运到灌浆籽粒基部的韧皮部(Ishimaru et al., 2001; Scofield et al., 2002, 2007)。OsSUT2编码的SUT位于液泡膜上, 负责将蔗糖从液泡转运至胞质, 其在叶肉细胞和维管束鞘中高表达, 在籽粒灌浆初始阶段的小穗枝梗及灌浆后7-8天的种皮中也有显著表达。ossut2突变体籽粒的千粒重下降, 但其对GFR的影响尚属未知(Eom et al., 2011)。通过同源比对调控玉米(Zea mays)籽粒灌浆的己糖和蔗糖转运蛋白SWEET (sugars will eventually be exported transporters)基因ZmSWEET4c, 鉴定了水稻中的同源基因OsSWEET4, 其负责将葡萄糖和果糖等己糖通过基底胚乳转移层从韧皮部运输到胚乳, 功能缺失突变体表现出严重的灌浆缺陷(Sosso et al., 2015)。对水稻灌浆籽粒中表达的其它SWEET基因进行研究, 发现OsSWEET11和OsSWEET15分别参与珠心组织突起处蔗糖的外排, 以及珠心表皮层和糊粉层交界处的糖类转运, 其中OsSWEET15的突变导致GFR显著降低(Ma et al., 2017; Yang et al., 2018)。2 转录和翻译调控基因对GFR的调节
2.1 转录因子相关基因
在水稻籽粒灌浆过程中, 糖类等物质代谢与运输以及胚乳发育受到转录水平、转录后水平、翻译水平和翻译后水平等多级复杂调控。目前研究较多的是基因转录水平上的籽粒灌浆调控机制, 已发现数个相关转录因子。MADS-box (MCM1、Agamous、Deficiens和SRF-box)转录因子因其包含高度保守的MADS结构域而得名, 多数参与花器官形态建成等发育过程。水稻MADS-box转录因子基因OsMADS6可调控多个AGPase基因(OsAGPS1、OsAGPL2和OsAGPL3)的表达, 其突变体籽粒灌浆发生严重缺陷, 淀粉积累减少(Zhang et al., 2010)。另一个MADS-box转录因子基因OsMADS29通过调控半胱氨酸蛋白酶和核苷酸结合位点-富含亮氨酸重复蛋白等基因的转录来调节授粉后母体组织的降解, 保证胚乳正常起始发育; 抑制OsMADS29的表达导致GFR下降, 籽粒发育异常(Yin and Xue, 2012)。NF-Y (nuclear factor-Y)转录因子一般由3种不同的亚基组成(NF-YA、NF-YB和NF-YC), 是一类异源多聚体转录因子。水稻NF-YB亚基基因OsNF-YB1在灌浆籽粒糊粉层中特异表达, 抑制OsNF-YB1的表达会降低GFR (Xu et al., 2016)。OsNF-YB1可以与NF-YC亚基OsNF-YC11/12以及AP2/ERF (APETALA2/ethylene-responsive factor)家族转录因子OsERF115互作形成蛋白复合体, 通过结合GCC盒和AP2/ERF转录因子结合基序, 在转录水平上直接调控参与糖和氨基酸等同化物转运的基因, 包括OsSUT1 (Xu et al., 2016; Xiong et al., 2019)。NF-YC12在胚乳中还与FLO6和胞质谷氨酰胺合成酶基因OsGS1;3的启动子结合, 直接调控后者的转录(Xiong et al., 2019)。此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究。RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(Onodera et al., 2001; Kawakatsu et al., 2009; Wang et al., 2013), OsDOF11直接正调控糖类转运蛋白基因OsSUT1、OsSWEET11和OsSWEET14的表达(Wu et al., 2018)。SERF1直接负调控RPBF以及淀粉粒结合淀粉合成酶基因GBSSI的转录(Schmidt et al., 2014)。RSR1负调控一系列I型淀粉合成酶基因的表达(Fu and Xue, 2010)。多梳蛋白(polycomb group)基因OsFIE2编码1个组蛋白H3甲基转移酶, 在染色质水平抑制HLH (helix-loop-helix)转录因子家族基因的转录, 进而影响一系列淀粉合成酶和贮藏蛋白相关基因的表达(Na et al., 2012; Nallamilli et al., 2013; Li et al., 2014; Liu et al., 2016; Cheng et al., 2020)。
2.2 microRNA
microRNA通过介导靶基因信使RNA的切割和降解, 在转录后水平调节靶基因的表达。microRNA在水稻籽粒灌浆过程中发挥重要的调节作用, 推测多个microRNA通过调节同化物代谢、基因转录调控和植物激素稳态等相关基因的表达而影响籽粒灌浆(Peng et al., 2013, 2014b; Yi et al., 2013)。Zhao等(2019)报道了1个在籽粒灌浆过程中表达量逐渐升高的microRNA——miR1432, 其通过靶向酰基辅酶A硫酯酶基因OsACOT的信使RNA, 影响脂肪酸代谢以及生长素和脱落酸的合成, 进而负调控GFR; 抑制miR1432的表达可以提高GFR, 过表达miR1432结合位点发生突变的OsACOT同样可提高GFR (Zhao et al., 2019)。该研究表明, miR1432的靶基因OsACOT可以正调控GFR; OsACOT参与脂肪酸去饱和及其碳链延长, 因此脂肪酸代谢可能也与GFR密切相关。2.3 蛋白化学修饰相关基因
研究发现, 编码Rho家族GTPase的水稻基因OsRac1在翻译后蛋白化学修饰水平上正调控GFR; 其负责丝裂原活化蛋白激酶OsMAPK6的磷酸化, 过表达该基因可以促进细胞分裂, 使籽粒增大、GFR升高, 而敲除该基因导致GFR降低(Zhang et al., 2019a)。另一项研究发现, 水稻14-3-3蛋白家族基因GF14f在蛋白化学修饰水平上负调控稻穗下部弱势粒的GFR, 其编码蛋白涉及蛋白丝氨酸残基磷酸化; GF14f与蔗糖水解、淀粉合成、三羧酸循环和糖酵解相关酶类存在互作, 而抑制GF14f的表达会使籽粒中AGPase、蔗糖合成酶和淀粉合成酶的活性增强(Zhang et al., 2019b)。3 粒型和粒重等性状相关QTL对GFR的作用
3.1 粒型相关QTL
根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性。目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR。其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1。编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(Li et al., 2011; Xu et al., 2015)。GS5通过竞争性结合油菜素内酯(brassinosteroid, BR)相关受体激酶OsBAK1-7的富含亮氨酸重复结构域, 抑制后者与膜类固醇结合蛋白OsMSBP1的互作, 进而阻止OsBAK1-7的胞吞作用而影响BR信号(Xu et al., 2015)。GW8编码1个受miR156调控的SPL (SQUAMOSA promoter-binding protein-like)家族转录因子OsSPL16, 其直接与另一个粒型相关QTL基因GL7/GW7的启动子结合, 抑制后者的表达(Wang et al., 2012)。GW8启动子区域的变异导致该基因的表达量改变, 其高表达促进横向细胞分裂, 抑制纵向细胞伸长, 因此使粒宽和GFR增高。GLW7编码另一个SPL转录因子OsSPL13, 在大粒热带粳稻中, 该基因5′UTR上一段串联重复导致其表达增强, 使细胞体积增大、粒长变长, 同时使GFR增高(Si et al., 2016)。GS2/GL2/GLW2编码受miR396调控的生长调控因子OsGRF4, miR396结合位点突变的等位基因在使水稻籽粒增大的同时, 也使GFR大幅升高(Hu et al., 2015; Che et al., 2016; Duan et al., 2016b; Li et al., 2016; Sun et al., 2016; Chen et al., 2019)。GS2/GL2/GLW2与转录共激活因子OsGIF1/2/3互作, 正调控多个粒型相关QTL基因(如GS5和GW8)、糖类代谢和运输相关基因(如OsCIN2和OsSWEET11)、光合作用相关基因以及BR信号途径相关基因的表达(Hu et al., 2015; Che et al., 2016; Li et al., 2018)。GSA1编码1个糖基转移酶UGT83A1, 影响黄酮介导的生长素极性运输及生长素相关基因的表达, 进而调控细胞分裂和增殖。非洲栽培稻(O. glaberrima) GSA1等位基因编码蛋白的保守氨基酸变异导致GSA1酶活降低, 使粒型变小、GFR降低(Dong et al., 2020)。目前至少发现3个粒型相关QTLs负调控GFRs, 分别为GW2、qGL3/GL3.1和GL7/GW7。控制粒宽和粒厚的GW2编码1个RING型E3泛素连接酶, 参与泛素化蛋白降解, 其功能缺失性等位基因可使颖壳细胞数目增加、GFR升高(Song et al., 2007)。GW2在染色体上紧邻泛素特异性蛋白酶基因OsUBP15, 两者在遗传上可能存在相互作用; OsUBP15编码1个去泛素酶, 在水稻显性大粒突变体lg1-D中, OsUBP15稳定性增强, 导致粒宽增加和GFR升高(Shi et al., 2019)。控制水稻粒长的qGL3/GL3.1编码1个丝氨酸/苏氨酸磷酸酶OsPPKL1, 功能缺失性等位基因使粒长增加、GFR升高(Qi et al., 2012; Zhang et al., 2012)。qGL3/GL3.1通过调控细胞周期蛋白Cyclin- T1; 3去磷酸化影响细胞分裂(Qi et al., 2012)。Gao等(2019)研究发现, qGL3/GL3.1可以通过调控蛋白激酶OsGSK3去磷酸化来影响BR信号通路, 进而发挥其调控作用。调控粒型的GL7/GW7编码1个与拟南芥LONGIFOLIA (又称TON1 RECRUITING MOTIF 2)蛋白同源的微管相关蛋白, 该位点17.1 kb的串联重复或者启动子区域变异均能上调GL7/GW7的表达量, 使颖壳纵向细胞分裂, 并减少横向细胞分裂, 导致颖壳变细长, 同时提高稻米品质, 但降低籽粒灌浆中期的GFR (Wang et al., 2015a, 2015b)。
3.2 粒重相关QTL
已克隆的2个粒重相关QTLs (TGW6和GW6a)也影响GFR。TGW6编码吲哚乙酸-葡萄糖水解酶, 通过控制吲哚乙酸供应影响胚乳合胞体阶段到细胞化阶段的转变, 从而控制胚乳细胞的数目和籽粒长度, 而功能缺失性等位基因导致粒重和粒长增加、GFR升高; TGW6不仅直接调控胚乳长度, 还间接参与从源到库的碳水化合物运输(Ishimaru et al., 2013)。GW6a编码1个拥有组蛋白乙酰转移酶活性的类GNAT蛋白OsglHAT1, 调控组蛋白H4的乙酰化水平, 其启动子区域的变异导致GW6a的表达增强, 促进细胞分裂, 从而使粒重和粒长增加、GFR升高(Song et al., 2015)。3.3 穗粒数相关QTL
GNP1 (Grain Number per Panicle 1)是调控水稻穗粒数的QTL, 其编码1个赤霉素(GA)氧化酶OsGA- 20ox1, 催化GA生物合成的倒数第2步反应(Wu et al., 2016)。GNP1启动子区域的变异导致该基因表达量上升, 通过转录因子KNOX的反馈调节增强穗分生组织中的细胞分裂素活性, 进而增强另一个GA分解代谢酶基因GA2oxs的表达, 降低2种GA (GA1和GA3)的积累, 最终提高籽粒数目和产量, 但同时降低结实率、穗数、粒重以及GFR (Wu et al., 2016; Zhai et al., 2020)。4 GFR相关QTL的分析和克隆
跟粒型和粒重一样, GFR也是复杂的数量性状, 对其进行QTL分析是鉴定育种可用的优异等位基因的有效策略。由于对GFR的测定费时费力, 水稻GFR相关QTL的研究相对缺乏, 对其遗传调控位点及分子机制所知甚少。由于水稻茎秆和叶鞘是源组织, 其中储存的非结构碳水化合物对于灌浆初期胚乳的发育非常重要(Tsukaguchi et al., 1996)。Nagata等(2002)利用回交自交系, 以灌浆期水稻茎秆和叶鞘中非结构碳水化合物的积累量(绝对总含量、每株含量和每穗含量)为指标, 在不同年份分别检测到9个和14个可能影响籽粒灌浆的QTLs, 其中有5个在不同年份被重复检测到。Takai等(2005)利用重组自交系, 进一步对水稻茎秆和叶鞘中非结构碳水化合物含量以及每穗籽粒充实率相关QTLs开展了3个不同灌浆时期的动态分析, 鉴定到2个分别位于第8和12号染色体上影响籽粒灌浆的主效QTLs。近年来, 先后有3项研究涉及水稻GFR相关QTL的分析。贾小丽等(2012)利用重组自交系在2个不同环境下对单个时期的GFR进行了QTL分析, 共鉴定到6个和4个加性QTLs以及4个环境互作QTLs。Liu等(2015)利用95个水稻品种对5个灌浆期GFR进行QTL分析, 共检测到31个位点。Liu等(2019)进一步利用回交自交系, 对GFR进行条件QTL分析和时序QTL分析, 分别检测到7个(其中1个在2个时期)和3个(其中1个在2个时期) QTLs, 共有3个QTLs同时被2种方法检测到, 并克隆了其中1个位于10号染色体长臂末端的GFR主效QTL——GFR1 (GRAIN-FILLING RATE 1)。GFR1编码1个膜蛋白, 与二磷酸合酮糖羧化酶小亚基OsRbcS互作, 可能通过参与卡尔文循环促进GFR。来自穞稻的GFR1等位基因存在非同义突变, 该等位可以加快光合速率, 促进胚乳细胞分裂, 增强OsCIN1的表达, 使胚乳和剑叶中的蔗糖、葡萄糖及果糖含量增加(Liu et al., 2019)。
5 总结与展望
GFR是重要的农艺性状和复杂的数量性状, 对GFR调控基因和优异等位变异进行挖掘和研究, 有助于实现水稻快速灌浆特性的精准育种, 从而提升水稻的产量和品质。目前, 关于GFR遗传分析的研究才刚刚起步, 对于GFR的分子调控机制和网络的认识还非常有限, 对GFR等灌浆相关特性和性状的分子遗传机制进行解析将是水稻等农作物研究领域的热点和突破点。随着显微CT等表型组学相关技术运用于籽粒灌浆研究(Hu et al., 2020b), 将有望实现水稻不同穗(主穗和分蘖穗)、不同穗位籽粒(强势粒与弱势粒)和不同环境条件下GFR的高通量实时测量, 推动GFR时空复杂性和环境可变性背后的分子遗传机制解析。具体地说, 今后应重点在以下几方面开展研究。 (1) 以GFR为直接研究对象的遗传和分子生物学研究相对有限, 未来需要运用显微CT等表型组学技术, 以特定部位和环境下的GFR为测量性状和直接指标, 开展诸如突变体库筛查、全基因组关联分析和多组学联合分析, 对GFR调控基因和等位变异进行系统鉴定和研究; (2) 粒型及其相关基因可以作用于GFR, 而GFR也会影响粒型, 但GFR是否对于粒型调控基因存在反馈调节机制目前并不清楚, 未来需要开展水稻粒型和GFR互作机制的相关研究; (3) 已知GFR相关基因主要影响库和流, 而较少影响源, 未来需要更多地聚焦于源组织调控相关基因对GFR的作用, 特别是对叶片和光合作用相关突变体进行GFR考察, 检测其是否影响或调控GFR; (4) GFR在籽粒灌浆过程中是动态变化的, 不同时期、不同穗和不同穗部的GFR可能受不同基因的影响, 涉及的分子调控机制也不同, 未来关于GFR的分子遗传研究仍需在时空调控上进一步细化; (5) GFR受多种环境因子的影响, 其背后的分子响应和调节机制有待详细解析, 尤其是涉及的关键调控位点和优异等位基因亟需鉴定, 其将有助于培育GFR对不良环境钝感的优良水稻品种。
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DOI:10.1093/pcp/pcg030URLPMID:12668768 [本文引用: 1]
In this paper we report the identification, cloning and expression analysis of four putative sucrose transporter (SUT) genes from rice, designated OsSUT2, 3, 4 and 5. Three of the four genes were identified through extensive searches of the recently published draft sequence of the rice genome. Along with the previously reported OsSUT1 we propose that these five genes comprise the rice SUT gene family. Complementary DNA clones were isolated for the four newly identified genes. The deduced proteins of all five SUT genes were predicted to contain 12 membrane-spanning helices and a domain highly conserved throughout all known plant SUTs, suggesting the four additional OsSUT genes encode functional SUTs. Reverse transcription-PCR analysis was performed in order to investigate the expression pattern of each member of the SUT family in rice. A differing but overlapping expression pattern was observed for each member of the SUT family at different stages through plant development. These results, together with the structural variations apparent from the deduced protein sequences, suggest that the five SUTs possess diverse roles in both sink and source tissues. We also discuss the classification and evolution of the rice SUT gene family, using a comparison of the gene structures and deduced amino acid sequences with other known plant SUT genes.
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DOI:10.1038/nplants.2015.195URLPMID:27250747 [本文引用: 2]
Given the continuously growing population and decreasing arable land, food shortage is becoming one of the most serious global problems in this century(1). Grain size is one of the determining factors for grain yield and thus is a prime target for genetic breeding(2,3). Although a number of quantitative trait loci (QTLs) associated with rice grain size have been identified in the past decade, mechanisms underlying their functions remain largely unknown(4,5). Here we show that a grain-length-associated QTL, GL2, has the potential to improve grain weight and grain yield up to 27.1% and 16.6%, respectively. We also show that GL2 is allelic to OsGRF4 and that it contains mutations in the miR396 targeting sequence. Because of the mutation, GL2 has a moderately increased expression level, which consequently activates brassinosteroid responses by upregulating a large number of brassinosteroid-induced genes to promote grain development. Furthermore, we found that GSK2, the central negative regulator of rice brassinosteroid signalling, directly interacts with OsGRF4 and inhibits its transcription activation activity to mediate the specific regulation of grain length by the hormone. Thus, this work demonstrates the feasibility of modulating specific brassinosteroid responses to improve plant productivity.
DOI:10.1111/pbi.13173URLPMID:31131526 [本文引用: 1]
Pyrophosphate-fructose 6-phosphate 1-phosphotransferase (PFP1) reversibly converts fructose 6-phosphate and pyrophosphate to fructose 1, 6-bisphosphate and orthophosphate during glycolysis, and has diverse functions in plants. However, mechanisms underlying the regulation of starch metabolism by PFP1 remain elusive. This study addressed the function of PFP1 in rice floury endosperm and defective grain filling. Compared with the wild type, pfp1-3 exhibited remarkably low grain weight and starch content, significantly increased protein and lipid content, and altered starch physicochemical properties and changes in embryo development. Map-based cloning revealed that pfp1-3 is a novel allele and encodes the regulatory beta-subunit of PFP1 (PFP1beta). Measurement of nicotinamide adenine dinucleotide (NAD+) showed that mutation of PFP1beta markedly decreased its enzyme activity. PFP1beta and three of four putative catalytic alpha-subunits of PFP1, PFP1alpha1, PFP1alpha2, and PFP1alpha4, interacted with each other to form a heterotetramer. Additionally, PFP1beta, PFP1alpha1 and PFP1alpha2 also formed homodimers. Furthermore, transcriptome analysis revealed that mutation of PFP1beta significantly altered expression of many essential enzymes in starch biosynthesis pathways. Concentrations of multiple lipid and glycolytic intermediates and trehalose metabolites were elevated in pfp1-3 endosperm, indicating that PFP1 modulates endosperm metabolism, potentially through reversible adjustments to metabolic fluxes. Taken together, these findings provide new insights into seed endosperm development and starch biosynthesis and will help in the breeding of rice cultivars with higher grain yield and quality.
DOI:10.1093/jxb/erz192URLPMID:31020332 [本文引用: 1]
Grain shape is controlled by quantitative trait loci (QTLs) in rice (Oryza sativa L.). A rice mutant (JF178) with long and large grains has been used in a breeding program for over a decade, but its genetic basis has been unclear. Here, a semi-dominant QTL, designated Large Grain Size 1 (LGS1), was cloned and the potential molecular mechanism of LGS1 function was studied. Near-isogenic lines (NILs) and a map-based approach were employed to clone the LGS1 locus. LGS1 encodes the OsGRF4 transcription factor and contains a 2 bp missense mutation in the coding region that coincides with the putative pairing site of miRNA396. The LGS1 transcript levels in the mutant line were found to be higher than the lgs1 transcript levels in the control plants, suggesting that the mutation might disrupt the pairing of the LGS1 mRNA with miR396. In addition to producing larger grains, LGS1 also enhanced cold tolerance at the seedling stage and increased the survival rate of seedlings after cold stress treatment. These findings indicate that the mutation in LGS1 appears to disturb the GRF4-miR396 stress response network and results in the development of enlarged grains and enhancement of cold tolerance in rice.
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URLPMID:20713616 [本文引用: 1]
DOI:10.1105/tpc.18.00836URLPMID:30923230 [本文引用: 1]
Brassinosteroids (BRs) are steroid hormones that play essential roles in plant growth and development. We previously cloned qGL3, a major quantitative trait locus regulating grain length in rice (Oryza sativa). The O. sativa japonica var N411 has extra-large grains compared with the O. sativa indica var 9311, and the recessive qgl3 allele from N411 contributes positively to grain length. qGL3 encodes a putative protein phosphatase with Kelch-like repeat domains, an ortholog of Arabidopsis (Arabidopsis thaliana) brassinosteroid-insensitive1 SUPPRESSOR1 (BSU1). BSU1 positively regulates BR signaling, while overexpression of qGL3 induced BR loss-of-function phenotypes. Both qGL3(N411) and qGL3(9311) physically interact with the rice glycogen synthase kinase 3 (GSK3)/SHAGGY-like kinase 3 (OsGSK3), an ortholog of Arabidopsis BR INSENSITIVE2 (BIN2). qGL3(9311) dephosphorylates OsGSK3, but qGL3(N411) lacks this activity. Knocking out OsGSK3 enhances BR signaling and induces nuclear localization of O. sativa BRASSINAZOLE RESISTANT1 (OsBZR1). Unlike the dephosphorylation of BIN2 (which leads to protein degradation) in Arabidopsis, qGL3 dephosphorylates and stabilizes OsGSK3 in rice. These results demonstrate that qGL3 suppresses BR signaling by regulating the phosphorylation and stability of OsGSK3, which modulates OsBZR1 phosphorylation and subcellular distribution. Our study clarifies the role of qGL3 in the regulation of grain length and provides insight into BR signaling, including the differences between rice and Arabidopsis.
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[本文引用: 2]
DOI:10.1093/pcp/pce148URLPMID:11673635 [本文引用: 2]
We analyzed the function of a rice sucrose transporter, OsSUT1, by using antisense rice. There was no difference between antisense and wild-type plants in carbohydrate content and photosynthetic ability of the flag leaves in the vegetative growth stage, suggesting that OsSUT1 may not play an important role in carbon metabolism, at least in these materials.
[本文引用: 1]
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DOI:10.1111/j.1365-313X.2009.03925.xURLPMID:19473328 [本文引用: 1]
The rice (Oryza sativa L.) basic leucine Zipper factor RISBZ1 and rice prolamin box binding factor (RPBF) are transcriptional activators of rice seed storage protein (SSP) genes in vivo. To ascertain the functions of these trans-activators in seed development, knock-down (KD) transgenic rice plants were generated in which the accumulation of RISBZ1 and RPBF was reduced in an endosperm-specific manner by co-suppression (KD-RISBZ1 and KD-RPBF). The accumulation of most SSPs changed little between individual KD mutants and wild-type plants, whereas a double KD mutant (KD-RISBZ1/KD-RPBF) resulted in a significant reduction of most SSP gene expression and accumulation. The reduction of both trans-activators also caused a greater reduction in seed starch accumulation than individual KD mutants. Storage lipids were accumulated at reduced levels in KD-RISBZ1 and KD-RISBZ1/KD-RPBF seeds. KD-RPBF and KD-RISBZ1/KD-RPBF seeds exhibited multi-layered aleurone cells. Gene expression of DEFECTIVE KERNEL1 (OsDEK1), CRINKLY4 (OsCR4) and SUPERNUMERARY ALEURONE LAYER 1 (OsSAL1) rice homologues was decreased in the KD mutants, suggesting that these genes are regulated by RISBZ1 and RPBF. These phenotypes suggest that combinatorial interactions between RISBZ1 and RPBF play an essential role during grain filling. The functional redundancy and compensation between RISBZ1 and RPBF possibly account for weak effects on the SSP levels in single KD mutants, and help maintain various processes during seed development in rice. Physical interaction between RISBZ1 and RPBF may ensure that these processes are carried out properly.
DOI:10.1038/s41586-018-0415-5URLPMID:30111841 [本文引用: 1]
Enhancing global food security by increasing the productivity of green revolution varieties of cereals risks increasing the collateral environmental damage produced by inorganic nitrogen fertilizers. Improvements in the efficiency of nitrogen use of crops are therefore essential; however, they require an in-depth understanding of the co-regulatory mechanisms that integrate growth, nitrogen assimilation and carbon fixation. Here we show that the balanced opposing activities and physical interactions of the rice GROWTH-REGULATING FACTOR 4 (GRF4) transcription factor and the growth inhibitor DELLA confer homeostatic co-regulation of growth and the metabolism of carbon and nitrogen. GRF4 promotes and integrates nitrogen assimilation, carbon fixation and growth, whereas DELLA inhibits these processes. As a consequence, the accumulation of DELLA that is characteristic of green revolution varieties confers not only yield-enhancing dwarfism, but also reduces the efficiency of nitrogen use. However, the nitrogen-use efficiency of green revolution varieties and grain yield are increased by tipping the GRF4-DELLA balance towards increased GRF4 abundance. Modulation of plant growth and metabolic co-regulation thus enables novel breeding strategies for future sustainable food security and a new green revolution.
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DOI:10.1038/ng.977URLPMID:22019783 [本文引用: 1]
Increasing crop yield is one of the most important goals of plant science research. Grain size is a major determinant of grain yield in cereals and is a target trait for both domestication and artificial breeding(1). We showed that the quantitative trait locus (QTL) GS5 in rice controls grain size by regulating grain width, filling and weight. GS5 encodes a putative serine carboxypeptidase and functions as a positive regulator of grain size, such that higher expression of GS5 is correlated with larger grain size. Sequencing of the promoter region in 51 rice accessions from a wide geographic range identified three haplotypes that seem to be associated with grain width. The results suggest that natural variation in GS5 contributes to grain size diversity in rice and may be useful in improving yield in rice and, potentially, other crops(2).
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URLPMID:31519786 [本文引用: 4]
DOI:10.1371/journal.pone.0164748URLPMID:27764161 [本文引用: 1]
Polycomb group (PcG) proteins have been shown to affect growth and development in plants. To further elucidate their role in these processes in rice, we isolated and characterized a rice mutant which exhibits dwarfism, reduced seed setting rate, defective floral organ, and small grains. Map-based cloning revealed that abnormal phenotypes were attributed to a mutation of the Fertilization Independent Endosperm 2 (OsFIE2) protein, which belongs to the PcG protein family. So we named the mutant as osfie2-1. Histological analysis revealed that the number of longitudinal cells in the internodes decreased in osfie2-1, and that lateral cell layer of the internodes was markedly thinner than wild-type. In addition, compared to wild-type, the number of large and small vascular bundles decreased in osfie2-1, as well as cell number and cell size in spikelet hulls. OsFIE2 is expressed in most tissues and the coded protein localizes in both nucleus and cytoplasm. Yeast two-hybrid and bimolecular fluorescence complementation assays demonstrated that OsFIE2 interacts with OsiEZ1 which encodes an enhancer of zeste protein previously identified as a histone methylation enzyme. RNA sequencing-based transcriptome profiling and qRT-PCR analysis revealed that some homeotic genes and genes involved in endosperm starch synthesis, cell division/expansion and hormone synthesis and signaling are differentially expressed between osfie2-1 and wild-type. In addition, the contents of IAA, GA3, ABA, JA and SA in osfie2-1 are significantly different from those in wild-type. Taken together, these results indicate that OsFIE2 plays an important role in the regulation of plant height and grain yield in rice.
DOI:10.1093/pcp/pcx040URLPMID:28371825 [本文引用: 1]
This study investigated the role of the sugar transporter OsSWEET11 during the early stage of rice caryopsis development using beta-glucoronidase (GUS) to represent its expression, together with clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9 (CRISPR-Cas9)-mediated knockout, cross-fertilization and RNA sequencing (RNA-seq) analyses. The results showed that OsSWEET11 was expressed strongly in developing caryopsis, particularly in the ovular vascular trace, nucellar epidermis and cross cells. The knockout of OsSWEET11 significantly decreased the sucrose concentration in the mutant embryo sacs and led to defective grain filling compared with that of the wild-type (WT) plant. Moreover, the expression of 2,549 genes in the mutant caryopsis was affected. The grain weight and seed setting percentage were also decreased in the mutants. The cross-fertilization of the mutant and WT rice revealed that the mutated maternal donor induced defective grain filling. These results strongly suggested that OsSWEET11 played an important role in sucrose release from maternal tissue to the maternal-filial interface during the early stage of caryopsis development. It might also induce sucrose release from the ovular vascular trace and cross cells of developing caryopsis. These findings bridge the gap in the understanding of post-phloem sugar transport during the early stage of rice caryopsis development.
DOI:10.1007/s11816-012-0229-0URL [本文引用: 1]
Seed development is a complex but orchestrated process that requires the fine-tuning of parentally governed gene expression, which is regulated by Polycomb proteins. Over the last decade, various Polycomb proteins have been identified and functionally characterized in plants, and it has been found that they form the PRC2 suppressor complex, which is involved in various developmental programs, including seed development. In this study, the function of the rice fertilization-independent endosperm gene OsFIE2, which expresses a protein homologous to the Arabidopsis Polycomb protein FIE, was characterized. We also characterized OsEZ1/OsiEZ1, another key component of the PRC2 complex. Both the OsFIE2 and OsEZ11 genes are strongly expressed in leaf and stem compared to other tissues, including root, anther, ovary, and ovule. We further examined whether OsFIE2 interacted with OsEZ1 using a yeast two-hybrid system. Interaction analysis showed that OsFIE2 interacted with OsEZ1 but not with Arabidopsis MEA protein. To examine the physiological roles of OsFIE2, 35S:OsFIE2 Arabidopsis lines were generated. Transgenic plants with 35S:OsFIE2 grew faster than wild-type plants during early development. Importantly, they produced bigger seed than the wild type, indicating that OsFIE2 may play an important role in seed size. In addition, we generated pOsFIE2:GUS plants to examine the spatial expression pattern of OsFIE2. GUS expression was detected in cotyledon but not in any other tissues, suggesting that OsFIE2 expression may be required to suppress homeotic genes in cotyledon.
[本文引用: 1]
DOI:10.1371/journal.pgen.1003322URLPMID:23505380 [本文引用: 1]
Cereal endosperm represents 60% of the calories consumed by human beings worldwide. In addition, cereals also serve as the primary feedstock for livestock. However, the regulatory mechanism of cereal endosperm and seed development is largely unknown. Polycomb complex has been shown to play a key role in the regulation of endosperm development in Arabidopsis, but its role in cereal endosperm development remains obscure. Additionally, the enzyme activities of the polycomb complexes have not been demonstrated in plants. Here we purified the rice OsFIE2-polycomb complex using tandem affinity purification and demonstrated its specific H3 methyltransferase activity. We found that the OsFIE2 gene product was responsible for H3K27me3 production specifically in vivo. Genetic studies showed that a reduction of OsFIE2 expression led to smaller seeds, partially filled seeds, and partial loss of seed dormancy. Gene expression and proteomics analyses found that the starch synthesis rate limiting step enzyme and multiple storage proteins are down-regulated in OsFIE2 reduction lines. Genome wide ChIP-Seq data analysis shows that H3K27me3 is associated with many genes in the young seeds. The H3K27me3 modification and gene expression in a key helix-loop-helix transcription factor is shown to be regulated by OsFIE2. Our results suggest that OsFIE2-polycomb complex positively regulates rice endosperm development and grain filling via a mechanism highly different from that in Arabidopsis.
DOI:10.1074/jbc.M007405200URLPMID:11133985 [本文引用: 1]
The GCN4 motif, a cis-element that is highly conserved in the promoters of cereal seed storage protein genes, plays a central role in controlling endosperm-specific expression. This motif is the recognition site for a basic leucine zipper transcriptional factor that belongs to the group of maize Opaque-2 (O2)-like proteins. Five different basic leucine zipper cDNA clones, designated RISBZ1-5, have been isolated from a rice seed cDNA library. The predicted gene products can be divided into two groups based on their amino acid sequences. Although all the RISBZ proteins are able to interact with the GCN4 motif, only RISBZ1 is capable of activating (more than 100-fold expression) the expression of a reporter gene under a minimal promoter fused to a pentamer of the GCN4 motif. Loss-of-function and gain-of-function experiments using the yeast GAL4 DNA binding domain revealed that the proline-rich N-terminal domain (27 amino acids in length) is responsible for transactivation. The RISBZ1 protein is capable of forming homodimers as well as heterodimers with other RISBZ subunit proteins. RISBZ1 gene expression is restricted to the seed, where it precedes the expression of storage protein genes. When the RISBZ1 promoter was transcriptionally fused to the beta-glucuronidase reporter gene and the chimeric gene was introduced into rice, the beta-glucuronidase gene is specifically expressed in aleurone and subaleurone layer of the developing endosperm. These findings suggest that the specific expression of transcriptional activator RISBZ1 gene may determine the endosperm specificity of the storage protein genes.
DOI:10.1111/tpj.12444URLPMID:24456533 [本文引用: 1]
Starch is the most widespread form of energy storage in the plant kingdom. Although many enzymes and related factors have been identified for starch biosynthesis, unknown players remain to be identified, given that it is a complicated and sophisticated process. The endosperm of rice (Oryza sativa) has been used for the study of starch synthesis. Here, we report the cloning and characterization of the FLOURY ENDOSPERM6 (FLO6) gene in rice. In the flo6 mutant, the starch content is decreased and the normal physicochemical features of starch are changed. Significantly, flo6 mutant endosperm cells show obvious defects in compound granule formation. Map-based cloning showed that FLO6 encodes a protein of unknown function. It harbors an N-terminal transit peptide that ensures its correct localization and functions in the plastid, and a C-terminal carbohydrate-binding module 48 (CBM48) domain that binds to starch. Furthermore, FLO6 can interact with isoamylase1 (ISA1) both in vitro and in vivo, whereas ISA1 does not bind to starch directly. We thus propose that FLO6 may act as a starch-binding protein involved in starch synthesis and compound granule formation through a direct interaction with ISA1 in developing rice seeds. Our data provide a novel insight into the role of proteins with the CBM48 domain in plant species.
URLPMID:23365650 [本文引用: 1]
DOI:10.1186/s12870-014-0196-4URLPMID:25052585 [本文引用: 1]
BACKGROUND: The inferior spikelets are defined to be those at portions where the grains receive less photosynthetic products during the seed development. The typical inferior spikelets are physically located on the proximal secondary branches in a rice panicle and traditionally characterized by a later flowering time and a slower grain-filling rate, compared to those so-called superior spikelets. Grains produced on the inferior spikelets are consequently under-developed and lighter in weight than those formed on the superior spikelets. MicroRNAs (miRNAs) are recognized as key players in regulating plant development through post-transcriptional gene regulations. We previously presented the evidence that miRNAs may influence grain-filling rate and played a role in determining the grain weight and yield in rice. RESULTS: In this study, further analyses of the expressed small RNAs in superior and inferior spikelets were conducted at five distinct developmental stages of grain development. Totally, 457 known miRNAs and 13 novel miRNAs were analyzed, showing a differential expression of 141 known miRNAs between superior and inferior spikelets with higher expression levels of most miRNAs associated with the superior than the inferior spikelets during the early stage of grain filling. Genes targeted by those differentially expressed miRNAs (i.e. miR156, miR164, miR167, miR397, miR1861, and miR1867) were recognized to play roles in multiple developmental and signaling pathways related to plant hormone homeostasis and starch accumulation. CONCLUSIONS: Our data established a complicated link between miRNA dynamics and the traditional role of hormones in grain filling and development, providing new insights into the widely accepted concepts of the so-called superior and inferior spikelets in rice production.
DOI:10.1038/cr.2012.151URLPMID:23147796 [本文引用: 2]
Increased crop yields are required to support rapid population growth worldwide. Grain weight is a key component of rice yield, but the underlying molecular mechanisms that control it remain elusive. Here, we report the cloning and characterization of a new quantitative trait locus (QTL) for the control of rice grain length, weight and yield. This locus, GL3.1, encodes a protein phosphatase kelch (PPKL) family - Ser/Thr phosphatase. GL3.1 is a member of the large grain WY3 variety, which is associated with weaker dephosphorylation activity than the small grain FAZ1 variety. GL3.1-WY3 influences protein phosphorylation in the spikelet to accelerate cell division, thereby resulting in longer grains and higher yields. Further studies have shown that GL3.1 directly dephosphorylates its substrate, Cyclin-T1;3, which has only been rarely studied in plants. The downregulation of Cyclin-T1;3 in rice resulted in a shorter grain, which indicates a novel function for Cyclin-T in cell cycle regulation. Our findings suggest a new mechanism for the regulation of grain size and yield that is driven through a novel phosphatase-mediated process that affects the phosphorylation of Cyclin-T1;3 during cell cycle progression, and thus provide new insight into the mechanisms underlying crop seed development. We bred a new variety containing the natural GL3.1 allele that demonstrated increased grain yield, which indicates that GL3.1 is a powerful tool for breeding high-yield crops.
DOI:10.1093/mp/sst131URLPMID:24046061 [本文引用: 1]
Grain quality is an important agricultural trait that is mainly determined by grain size and composition. Here, we characterize the role of the rice transcription factor (TF) SALT-RESPONSIVE ERF1 (SERF1) during grain development. Through genome-wide expression profiling and chromatin immunoprecipitation, we found that SERF1 directly regulates RICE PROLAMIN-BOX BINDING FACTOR (RPBF), a TF that functions as a positive regulator of grain filling. Loss of SERF1 enhances RPBF expression resulting in larger grains with increased starch content, while SERF1 overexpression represses RPBF resulting in smaller grains. Consistently, during grain filling, starch biosynthesis genes such as GRANULE-BOUND STARCH SYNTHASEI (GBSSI), STARCH SYNTHASEI (SSI), SSIIIa, and ADP-GLUCOSE PYROPHOSPHORYLASE LARGE SUBUNIT2 (AGPL2) are up-regulated in SERF1 knockout grains. Moreover, SERF1 is a direct upstream regulator of GBSSI. In addition, SERF1 negatively regulates germination by controlling RPBF expression, which mediates the gibberellic acid (GA)-induced expression of RICE AMYLASE1A (RAmy1A). Loss of SERF1 results in more rapid seedling establishment, while SERF1 overexpression has the opposite effect. Our study reveals that SERF1 represents a negative regulator of grain filling and seedling establishment by timing the expression of RPBF.
DOI:10.1093/jxb/erm153URLPMID:17728297 [本文引用: 1]
The roles of the rice sucrose transporter, OsSUT1, have previously been examined in filling grain, germination, and early seedling growth. In the current work, the role that OsSUT1 plays in the transport of assimilate along the entire long-distance pathway, from the flag leaf blade to the base of the filling grain, was investigated. OsSUT1 promoter::GUS (beta-glucuronidase) reporter gene analysis and immunolocalization revealed that both OsSUT1 promoter::GUS activity and OsSUT protein were present in the mature phloem of all the vegetative tissues involved in the long-distance assimilate transport pathway during grain filling. In addition, expression was observed in the flag leaf blade and sheath prior to heading. The OsSUT1 promoter::GUS activity appeared to be largely confined to the companion cells within the phloem, whereas the protein localized to both the sieve tubes and the companion cells. RT-PCR analysis confirmed that the OsSUT1 transcript is expressed in the uppermost internode of the rice plant (internode-1). These OsSUT localization data were related to measurements of starch and soluble sugar content of these tissues, and localization of the carbohydrate reserves stored in the stem. Results from dye feeding experiments, to examine cellular connections, revealed a symplastic continuity between the phloem and surrounding parenchyma in the flag leaf blade, sheath, and internode-1 tissues. It is proposed that OsSUT1 may primarily play a role in phloem loading of sucrose retrieved from the apoplasm along the transport pathway.
URLPMID:32689529 [本文引用: 1]
DOI:10.1104/pp.19.00065URLPMID:30796160 [本文引用: 1]
Ubiquitination and deubiquitination are reversible processes that play crucial roles in regulating organ size in plants. However, information linking deubiquitination and seed size in rice (Oryza sativa) is limited. Here, we characterized a dominant large-grain mutant, large grain1-D (lg1-D), with a 30.8% increase in seed width and a 34.5% increase in 1,000-grain weight relative to the wild type. The lg1-D mutant had more cells oriented in the lateral direction of the spikelet hull compared with the wild type. Map-based cloning showed that LG1 encodes a constitutively expressed ubiquitin-specific protease15 (OsUBP15) that possesses deubiquitination activity in vitro. Loss-of-function and down-regulated expression of OsUBP15 produced narrower and smaller grains than the control. A set of in vivo experiments indicated that the mutant Osubp15 had enhanced protein stability relative to wild-type OsUBP15. Further experiments verified that OsDA1 directly interacted with OsUBP15. Genetic data indicated that OsUBP15 and GRAIN WIDTH 2 (GW2) were not independent in regulating grain width and size. In summary, we identified OsUBP15 as a positive regulator of grain width and size in rice and provide a promising strategy for improvement of grain yield by pyramiding OsUBP15 and gw2.
URLPMID:26950093 [本文引用: 1]
DOI:10.1038/ng2014URLPMID:17417637 [本文引用: 1]
Grain weight is one of the most important components of grain yield and is controlled by quantitative trait loci (QTLs) derived from natural variations in crops. However, the molecular roles of QTLs in the regulation of grain weight have not been fully elucidated. Here, we report the cloning and characterization of GW2, a new QTL that controls rice grain width and weight. Our data show that GW2 encodes a previously unknown RING-type protein with E3 ubiquitin ligase activity, which is known to function in the degradation by the ubiquitin-proteasome pathway. Loss of GW2 function increased cell numbers, resulting in a larger (wider) spikelet hull, and it accelerated the grain milk filling rate, resulting in enhanced grain width, weight and yield. Our results suggest that GW2 negatively regulates cell division by targeting its substrate(s) to proteasomes for regulated proteolysis. The functional characterization of GW2 provides insight into the mechanism of seed development and is a potential tool for improving grain yield in crops.
DOI:10.1073/pnas.1421127112URLPMID:25535376 [本文引用: 1]
Grain weight is an important crop yield component; however, its underlying regulatory mechanisms are largely unknown. Here, we identify a grain-weight quantitative trait locus (QTL) encoding a new-type GNAT-like protein that harbors intrinsic histone acetyltransferase activity (OsglHAT1). Our genetic and molecular evidences pinpointed the QTL-OsglHAT1's allelic variations to a 1.2-kb region upstream of the gene body, which is consistent with its function as a positive regulator of the traits. Elevated OsglHAT1 expression enhances grain weight and yield by enlarging spikelet hulls via increasing cell number and accelerating grain filling, and increases global acetylation levels of histone H4. OsglHAT1 localizes to the nucleus, where it likely functions through the regulation of transcription. Despite its positive agronomical effects on grain weight, yield, and plant biomass, the rare allele elevating OsglHAT1 expression has so far escaped human selection. Our findings reveal the first example, to our knowledge, of a QTL for a yield component trait being due to a chromatin modifier that has the potential to improve crop high-yield breeding.
DOI:10.1038/ng.3422URLPMID:26523777 [本文引用: 1]
Carbohydrate import into seeds directly determines seed size and must have been increased through domestication. However, evidence of the domestication of sugar translocation and the identities of seed-filling transporters have been elusive. Maize ZmSWEET4c, as opposed to its sucrose-transporting homologs, mediates transepithelial hexose transport across the basal endosperm transfer layer (BETL), the entry point of nutrients into the seed, and shows signatures indicative of selection during domestication. Mutants of both maize ZmSWEET4c and its rice ortholog OsSWEET4 are defective in seed filling, indicating that a lack of hexose transport at the BETL impairs further transfer of sugars imported from the maternal phloem. In both maize and rice, SWEET4 was likely recruited during domestication to enhance sugar import into the endosperm.
DOI:10.1016/s1360-1385(99)01470-3URLPMID:10498964 [本文引用: 1]
Sink organs of most plant species are supplied with carbon and energy in the form of sucrose. The channeling of sucrose into sink metabolism requires its cleavage by several isoforms of invertase and sucrose synthase, which are localized in different subcellular compartments. These activities regulate the entry of sucrose into distinct biochemical pathways, such as respiration or biosynthesis of cell wall polysaccharides and storage reserves. Other vital roles for the sucrose-cleaving enzymes include invertase activity at the site of phloem unloading and vacuolar invertase and sucrose synthase in sink organs, which drives the long-distance transport of sucrose. In addition, invertases have been implicated in the defense response and in turgor-driven cell expansion, and sucrose synthase expression is associated with low temperature and anaerobiosis responses. Finally, because sugars also regulate gene expression, the sucrose-cleaving enzymes play a fundamental role in controlling cell differentiation and development.
DOI:10.1111/jipb.12473URLPMID:26936408 [本文引用: 1]
Traits such as grain shape, panicle length and seed shattering, play important roles in grain yield and harvest. In this study, the cloning and functional analysis of PANICLE TRAITS 2 (PT2), a novel gene from the Indica rice Chuandali (CDL), is reported. PT2 is synonymous with Growth-Regulating Factor 4 (OsGRF4), which encodes a growth-regulating factor that positively regulates grain shape and panicle length and negatively regulates seed shattering. Higher expression of OsGRF4 is correlated with larger grain, longer panicle and lower seed shattering. A unique OsGRF4 mutation, which occurs at the OsmiRNA396 target site of OsGRF4, seems to be associated with high levels of OsGRF4 expression, and results in phenotypic difference. Further research showed that OsGRF4 regulated two cytokinin dehydrogenase precursor genes (CKX5 and CKX1) resulting in increased cytokinin levels, which might affect the panicle traits. High storage capacity and moderate seed shattering of OsGRF4 may be useful in high-yield breeding and mechanized harvesting of rice. Our findings provide additional insight into the molecular basis of panicle growth.
DOI:10.1093/jxb/eri209URLPMID:15983016 [本文引用: 1]
Grain-filling is a crucial process that determines final grain yield in rice (Oryza sativa L.). To understand the genetic basis of dynamics of grain-filling, quantitative trait locus (QTL) analysis was conducted using time-related phenotypic data on grain-filling collected from a population of 155 recombinant inbred lines (F12), derived from a cross between Milyang 23 and Akihikari. Two QTLs detected on chromosomes 8 and 12 were strongly associated with increased filling percentage per panicle. These QTLs were not linked with those controlling spikelet numbers per panicle. This result confers the possibility of improving grain-filling together with an enlargement of sink size. The QTL for filling percentage per panicle on chromosome 8 exactly overlapped that for non-structural carbohydrate (NSC) content in the culm and leaf sheaths during grain-filling, and the Milyang 23 allele associated with increased grain-filling percentage per panicle was associated with decreased NSC content. Therefore, this QTL may be directly involved in NSC translocation from the culm and leaf sheaths to panicle. In addition, the Milyang 23 alleles of QTLs associated with greater spikelet number per panicle on chromosomes 1 and 6 were also related with a reduction in NSC content in the culm and leaf sheaths during grain-filling. These results indicate that NSC dynamics during grain-filling is partly dependent on sink size. NSC accumulation in the culm and leaf sheaths at the heading stage was mainly controlled by different genetic regulations from NSC dynamics during grain-filling. Nitrogen dynamics during grain-filling may also be involved in carbohydrate dynamics.
[本文引用: 1]
DOI:10.1038/ng.220URLPMID:18820698 [本文引用: 2]
DOI:10.1186/1471-2148-10-108URLPMID:20416079 [本文引用: 1]
BACKGROUND: Various evolutionary models have been proposed to interpret the fate of paralogous duplicates, which provides substrates on which evolution selection could act. In particular, domestication, as a special selection, has played important role in crop cultivation with divergence of many genes controlling important agronomic traits. Recent studies have indicated that a pair of duplicate genes was often sub-functionalized from their ancestral functions held by the parental genes. We previously demonstrated that the rice cell-wall invertase (CWI) gene GIF1 that plays an important role in the grain-filling process was most likely subjected to domestication selection in the promoter region. Here, we report that GIF1 and another CWI gene OsCIN1 constitute a pair of duplicate genes with differentiated expression and function through independent selection. RESULTS: Through synteny analysis, we show that GIF1 and another cell-wall invertase gene OsCIN1 were paralogues derived from a segmental duplication originated during genome duplication of grasses. Results based on analyses of population genetics and gene phylogenetic tree of 25 cultivars and 25 wild rice sequences demonstrated that OsCIN1 was also artificially selected during rice domestication with a fixed mutation in the coding region, in contrast to GIF1 that was selected in the promoter region. GIF1 and OsCIN1 have evolved into different expression patterns and probable different kinetics parameters of enzymatic activity with the latter displaying less enzymatic activity. Overexpression of GIF1 and OsCIN1 also resulted in different phenotypes, suggesting that OsCIN1 might regulate other unrecognized biological process. CONCLUSION: How gene duplication and divergence contribute to genetic novelty and morphological adaptation has been an interesting issue to geneticists and biologists. Our discovery that the duplicated pair of GIF1 and OsCIN1 has experienced sub-functionalization implies that selection could act independently on each duplicate towards different functional specificity, which provides a vivid example for evolution of genetic novelties in a model crop. Our results also further support the established hypothesis that gene duplication with sub-functionalization could be one solution for genetic adaptive conflict.
URLPMID:23846875 [本文引用: 1]
DOI:10.1038/ng.3352URLPMID:26147620 [本文引用: 1]
The deployment of heterosis in the form of hybrid rice varieties has boosted grain yield, but grain quality improvement still remains a challenge. Here we show that a quantitative trait locus for rice grain quality, qGW7, reflects allelic variation of GW7, a gene encoding a TONNEAU1-recruiting motif protein with similarity to C-terminal motifs of the human centrosomal protein CAP350. Upregulation of GW7 expression was correlated with the production of more slender grains, as a result of increased cell division in the longitudinal direction and decreased cell division in the transverse direction. OsSPL16 (GW8), an SBP-domain transcription factor that regulates grain width, bound directly to the GW7 promoter and repressed its expression. The presence of a semidominant GW7(TFA) allele from tropical japonica rice was associated with higher grain quality without the yield penalty imposed by the Basmati gw8 allele. Manipulation of the OsSPL16-GW7 module thus represents a new strategy to simultaneously improve rice yield and grain quality.
DOI:10.1038/ng.2327URLPMID:22729225 [本文引用: 1]
Grain size and shape are important components of grain yield and quality and have been under selection since cereals were first domesticated. Here, we show that a quantitative trait locus GW8 is synonymous with OsSPL16, which encodes a protein that is a positive regulator of cell proliferation. Higher expression of this gene promotes cell division and grain filling, with positive consequences for grain width and yield in rice. Conversely, a loss-of-function mutation in Basmati rice is associated with the formation of a more slender grain and better quality of appearance. The correlation between grain size and allelic variation at the GW8 locus suggests that mutations within the promoter region were likely selected in rice breeding programs. We also show that a marker-assisted strategy targeted at elite alleles of GS3 and OsSPL16 underlying grain size and shape can be effectively used to simultaneously improve grain quality and yield.
DOI:10.1038/ng.3346URLPMID:26147619 [本文引用: 1]
Copy number variants (CNVs) are associated with changes in gene expression levels and contribute to various adaptive traits. Here we show that a CNV at the Grain Length on Chromosome 7 (GL7) locus contributes to grain size diversity in rice (Oryza sativa L.). GL7 encodes a protein homologous to Arabidopsis thaliana LONGIFOLIA proteins, which regulate longitudinal cell elongation. Tandem duplication of a 17.1-kb segment at the GL7 locus leads to upregulation of GL7 and downregulation of its nearby negative regulator, resulting in an increase in grain length and improvement of grain appearance quality. Sequence analysis indicates that allelic variants of GL7 and its negative regulator are associated with grain size diversity and that the CNV at the GL7 locus was selected for and used in breeding. Our work suggests that pyramiding beneficial alleles of GL7 and other yield- and quality-related genes may improve the breeding of elite rice varieties.
DOI:10.1111/jipb.12510URLPMID:27957808 [本文引用: 2]
Rice grain filling determines grain weight, final yield and grain quality. Here, a rice defective grain filling mutant, gif2, was identified. Grains of gif2 showed a slower filling rate and a significant lower final grain weight and yield compared to wild-type. The starch content in gif2 was noticeably decreased and its physicochemical properties were also altered. Moreover, gif2 endosperm cells showed obvious defects in compound granule formation. Positional cloning identified GIF2 to encode an ADP-glucose pyrophosphorylase (AGP) large subunit, AGPL2; consequently, AGP enzyme activity in gif2 endosperms was remarkably decreased. GIF2 is mainly expressed in developing grains and the coded protein localizes in the cytosol. Yeast two hybrid assay showed that GIF2 interacted with AGP small subunits OsAGPS1, OsAGPS2a and OsAGPS2b. Transcript levels for granule-bound starch synthase, starch synthase, starch branching enzyme and starch debranching enzyme were distinctly elevated in gif2 grains. In addition, the level of nucleotide diversity of the GIF2 locus was extremely low in both cultivated and wild rice. All of these results suggest that GIF2 plays important roles in the regulation of grain filling and starch biosynthesis during caryopsis development, and that it has been preserved during selection throughout domestication of modern rice.
DOI:10.1371/journal.pgen.1006386URLPMID:27764111 [本文引用: 2]
Cytokinins and gibberellins (GAs) play antagonistic roles in regulating reproductive meristem activity. Cytokinins have positive effects on meristem activity and maintenance. During inflorescence meristem development, cytokinin biosynthesis is activated via a KNOX-mediated pathway. Increased cytokinin activity leads to higher grain number, whereas GAs negatively affect meristem activity. The GA biosynthesis genes GA20oxs are negatively regulated by KNOX proteins. KNOX proteins function as modulators, balancing cytokinin and GA activity in the meristem. However, little is known about the crosstalk among cytokinin and GA regulators together with KNOX proteins and how KNOX-mediated dynamic balancing of hormonal activity functions. Through map-based cloning of QTLs, we cloned a GA biosynthesis gene, Grain Number per Panicle1 (GNP1), which encodes rice GA20ox1. The grain number and yield of NIL-GNP1TQ were significantly higher than those of isogenic control (Lemont). Sequence variations in its promoter region increased the levels of GNP1 transcripts, which were enriched in the apical regions of inflorescence meristems in NIL-GNP1TQ. We propose that cytokinin activity increased due to a KNOX-mediated transcriptional feedback loop resulting from the higher GNP1 transcript levels, in turn leading to increased expression of the GA catabolism genes GA2oxs and reduced GA1 and GA3 accumulation. This rebalancing process increased cytokinin activity, thereby increasing grain number and grain yield in rice. These findings uncover important, novel roles of GAs in rice florescence meristem development and provide new insights into the crosstalk between cytokinin and GA underlying development process.
DOI:10.1016/j.molp.2018.04.002URLPMID:29656028 [本文引用: 1]
Sucrose is produced in mesophyll cells and transferred into phloem cells before it is delivered long-distance to sink tissues. However, little is known about how sucrose transport is regulated in plants. Here, we identified a T-DNA insertional mutant of Oryza sativa DNA BINDING WITH ONE FINGER 11 (OsDOF11), which is expressed in the vascular cells of photosynthetic organs and in various sink tissues. The osdof11 mutant plants are semi-dwarf and have fewer tillers and smaller panicles as compared with wild-type (WT) plants. Although sucrose enhanced root elongation in young WT seedlings, this enhancement did not occur in osdof11 seedlings due to reduced sucrose uptake. Sugar transport rate analyses revealed that less sugar was transported in osdof11 plants than in the WT. Expression of four Sucrose Transporter (SUT) genes-OsSUT1, OsSUT3, OsSUT4, and OsSUT5-as well as two Sugars Will Eventually be Exported Transporters (SWEET) genes, OsSWEET11 and OsSWEET14, was altered in various organs of the mutant, including the leaves. Chromatin immunoprecipitation assays showed that OsDOF11 directly binds the promoter regions of SUT1, OsSWEET11, and OsSWEET14, indicating that the expression of these transporters responsible for sucrose transport via apoplastic loading is coordinately controlled by OsDOF11. We also observed that osdof11 mutant plants were less susceptible to infection by Xanthomonas oryzae pathovar oryzae, suggesting that OsDOF11 participates in sugar distribution during pathogenic invasion. Collectively, these results suggest that OsDOF11 modulates sugar transport by regulating the expression of both SUT and SWEET genes in rice.
DOI:10.1093/jxb/erz168URLPMID:31211389 [本文引用: 2]
Starch and storage proteins, the primary storage substances of cereal endosperm, are a major source of food for humans. However, the transcriptional regulatory networks of the synthesis and accumulation of storage substances remain largely unknown. Here, we identified a rice endosperm-specific gene, NF-YC12, that encodes a putative nuclear factor-Y transcription factor subunit C. NF-YC12 is expressed in the aleurone layer and starchy endosperm during grain development. Knockout of NF-YC12 significantly decreased grain weight as well as altering starch and protein accumulation and starch granule formation. RNA-sequencing analysis revealed that in the nf-yc12 mutant genes related to starch biosynthesis and the metabolism of energy reserves were enriched in the down-regulated category. In addition, starch and protein contents in seeds differed between NF-YC12-overexpression lines and the wild-type. NF-YC12 was found to interact with NF-YB1. ChIP-qPCR and yeast one-hybrid assays showed that NF-YC12 regulated the rice sucrose transporter OsSUT1 in coordination with NF-YB1 in the aleurone layer. In addition, NF-YC12 was directly bound to the promoters of FLO6 (FLOURY ENDOSPERM6) and OsGS1;3 (glutamine synthetase1) in developing endosperm. This study demonstrates a transcriptional regulatory network involving NF-YC12, which coordinates multiple pathways to regulate endosperm development and the accumulation of storage substances in rice seeds.
URLPMID:25711711 [本文引用: 2]
URLPMID:27803124 [本文引用: 2]
DOI:10.1111/nph.15004URLPMID:29393510 [本文引用: 1]
Despite the relevance of seed-filling mechanisms for crop yield, we still have only a rudimentary understanding of the transport processes that supply the caryopsis with sugars. We hypothesized that SWEET sucrose transporters may play important roles in nutrient import pathways in the rice caryopsis. We used a combination of mRNA quantification, histochemical analyses, translational promoter-reporter fusions and analysis of knockout mutants created by genomic editing to evaluate the contribution of SWEET transporters to seed filling. In rice caryopses, SWEET11 and 15 had the highest mRNA levels and proteins localized to four key sites: all regions of the nucellus at early stages; the nucellar projection close to the dorsal vein; the nucellar epidermis that surrounds the endosperm; and the aleurone. ossweet11;15 double knockout lines accumulated starch in the pericarp, whereas caryopses did not contain a functional endosperm. Jointly, SWEET11 and 15 show all the hallmarks of being necessary for seed filling with sucrose efflux functions at the nucellar projection and a role in transfer across the nucellar epidermis/aleurone interface, delineating two major steps for apoplasmic seed filling, observations that are discussed in relation to observations made in rice and barley regarding the relative prevalence of these two potential import routes.
DOI:10.1111/nph.2006.169.issue-2URLPMID:16411926 [本文引用: 1]
Monocarpic plants require the initiation of whole-plant senescence to remobilize and transfer assimilates pre-stored in vegetative tissues to grains. Delayed whole-plant senescence caused by either heavy use of nitrogen fertilizer or adoption of lodging-resistant cultivars/hybrids that remain green when the grains are due to ripen results in a low harvest index with much nonstructural carbohydrate (NSC) left in the straw. Usually, water stress during the grain-filling period induces early senescence, reduces photosynthesis, and shortens the grain-filling period; however, it increases the remobilization of NSC from the vegetative tissues to the grain. If mild soil drying is properly controlled during the later grain-filling period in rice (Oryza sativa) and wheat (Triticum aestivum), it can enhance whole-plant senescence, lead to faster and better remobilization of carbon from vegetative tissues to grains, and accelerate the grain-filling rate. In cases where plant senescence is unfavorably delayed, such as by heavy use of nitrogen and the introduction of hybrids with strong heterosis, the gain from the enhanced remobilization and accelerated grain-filling rate can outweigh the loss of reduced photosynthesis and the shortened grain-filling period, leading to an increased grain yield, better harvest index and higher water-use efficiency.
DOI:10.1093/jxb/erp348URLPMID:19959608 [本文引用: 2]
Modern rice (Oryza sativa L.) cultivars, especially the newly bred 'super' rice, have numerous spikelets on a panicle with a large yield capacity. However, these cultivars often fail to achieve their high yield potential due to poor grain-filling of later-flowering inferior spikelets (in contrast to the earlier-flowering superior spikelets). Conventional thinking to explain the poor grain-filling is the consequence of carbon limitation. Recent studies, however, have shown that carbohydrate supply should not be the major problem because they have adequate sucrose at their initial grain-filling stage. The low activities of key enzymes in carbon metabolism may contribute to the poor grain-filling. Proper field practices, such as moderate soil drying during mid- and late grain-filling stages, could solve some problems in poor grain-filling. Further studies are needed by molecular approaches to investigate the signal transport, the hormonal action, the gene expressions, and the biochemical processes in inferior spikelets.
DOI:10.1104/pp.127.1.315URLPMID:11553759 [本文引用: 1]
Lodging-resistant rice (Oryza sativa) cultivars usually show slow grain filling when nitrogen is applied in large amounts. This study investigated the possibility that a hormonal change may mediate the effect of water deficit that enhances whole plant senescence and speeds up grain filling. Two rice cultivars showing high lodging resistance and slow grain filling were field grown and applied with either normal or high amount nitrogen (HN) at heading. Well-watered and water-stressed (WS) treatments were imposed 9 days post anthesis to maturity. Results showed that WS increased partitioning of fixed (14)CO(2) into grains, accelerated the grain filling rate but shortened the grain filling period, whereas the HN did the opposite way. Cytokinin (zeatin + zeatin riboside) and indole-3-acetic acid contents in the grains transiently increased at early filling stage and WS treatments hastened their declines at the late grain filling stage. Gibberellins (GAs; GA(1) + GA(4)) in the grains were also high at early grain filling but HN enhanced, whereas WS substantially reduced, its accumulation. Opposite to GAs, abscisic acid (ABA) in the grains was low at early grain filling but WS remarkably enhanced its accumulation. The peak values of ABA were significantly correlated with the maximum grain filling rates (r = 0.92**, P < 0.01) and the partitioning of fixed (14)C into grains (r = 0.95**, P < 0.01). Exogenously applied ABA on pot-grown HN rice showed similar results as those by WS. Results suggest that an altered hormonal balance in rice grains by water stress during grain filling, especially a decrease in GAs and an increase in ABA, enhances the remobilization of prestored carbon to the grains and accelerates the grain filling rate.
DOI:10.1371/journal.pone.0057863URLPMID:23469249 [本文引用: 1]
MicroRNAs (miRNAs) have been shown to play crucial roles in the regulation of plant development. In this study, high-throughput RNA-sequencing technology was used to identify novel miRNAs, and to reveal miRNAs expression patterns at different developmental stages during rice (Oryza sativa L.) grain filling. A total of 434 known miRNAs (380, 402, 390 and 392 at 5, 7, 12 and 17 days after fertilization, respectively.) were obtained from rice grain. The expression profiles of these identified miRNAs were analyzed and the results showed that 161 known miRNAs were differentially expressed during grain development, a high proportion of which were up-regulated from 5 to 7 days after fertilization. In addition, sixty novel miRNAs were identified, and five of these were further validated experimentally. Additional analysis showed that the predicted targets of the differentially expressed miRNAs may participate in signal transduction, carbohydrate and nitrogen metabolism, the response to stimuli and epigenetic regulation. In this study, differences were revealed in the composition and expression profiles of miRNAs among individual developmental stages during the rice grain filling process, and miRNA editing events were also observed, analyzed and validated during this process. The results provide novel insight into the dynamic profiles of miRNAs in developing rice grain and contribute to the understanding of the regulatory roles of miRNAs in grain filling.
DOI:10.1105/tpc.111.094854URLPMID:22408076 [本文引用: 1]
The MADS box transcription factors are critical regulators of rice (Oryza sativa) reproductive development. Here, we here report the functional characterization of a rice MADS box family member, MADS29, which is preferentially expressed in the nucellus and the nucellar projection. Suppressed expression of MADS29 resulted in abnormal seed development; the seeds were shrunken, displayed a low grain-filling rate and suppressed starch biosynthesis, and contained abnormal starch granules. Detailed analysis indicated that the abnormal seed development is due to defective programmed cell death `(PCD) of the nucellus and nucellar projection, which was confirmed by a TUNEL assay and transcriptome analysis. Further studies showed that expression of MADS29 is induced by auxin and MADS29 protein binds directly to the putative promoter regions of genes that encode a Cys protease and nucleotide binding site-Leu-rich repeat proteins, thereby stimulating the PCD. This study identifies MADS29 as a key regulator of early rice seed development by regulating the PCD of maternal tissues. It provides informative clues to elucidate the regulatory mechanism of maternal tissue degradation after fertilization and to facilitate the studies of endosperm development and seed filling.
DOI:10.3389/fpls.2020.00933URLPMID:32655609 [本文引用: 1]
Rice yield potential is largely determined by the balance among source capacity, sink strength, and flow fluency. Our previous study indicated that the gene GNP1 encoding gibberellin biosynthesis gene GA20ox1 affects grain number per panicle (GNP) in rice, thus resulting in increase of grain yield. To clarify GNP1 effect on sink, source and flow in regulating rice grain yield, we compared Lemont, a japonica (geng) cultivar, with its near-isogenic line (NIL-GNP1 (TQ)) in Lemont background with introgression of the allele at GNP1 from Teqing, a high-yielding indica (xian) cultivar. NIL-GNP1 (TQ) exhibited averagely 32.8% more GNP than Lemont with the compensation by reduced seed setting rate, panicle number and single-grain weight. However, NIL-GNP1 (TQ) still produced averagely 7.2% higher grain yield than Lemont in two years, mainly attributed to significantly more filled grain number per panicle, and greater vascular system contributing to photoassimilates transport to spikelets. The significantly decreased grain weight of superior spikelets (SS) in NIL-GNP1 (TQ) was ascribed to a significant decrease of grain size while the significantly decreased grain weight of inferior spikelets (IS) ascribed to both grain size and poor grain-filling as compared with Lemont. The low activities of key enzymes of carbon metabolism might account for the poor grain-filling in IS, which resulted in more unfilled grains or small grain bulk density in NIL-GNP1 (TQ). In addition, low seed setting rate and grain weight of IS in NIL-GNP1 (TQ) might be partially resulted from significantly lower carbohydrate accumulation in culms and leaf sheath before heading compared with Lemont. Our results indicated that significantly increased GNP from introgression of GNP1 (TQ) into Lemont did not highly significantly improve grain yield of NIL-GNP1 (TQ) as expected, due primarily to significant low sink activities in IS and possible insufficient source supply which didn't fully meet the increased sink capacity. The results provided useful information for improving rice yield potential through reasonably introgressing or pyramiding the favorable alleles underlying source-related or panicle number traits by marker-assisted selection.
DOI:10.1111/j.1365-313X.2010.04354.xURLPMID:20822505 [本文引用: 1]
MADS-box transcription factors are known for their roles in plant growth and development. The regulatory mechanisms of spatial and temporal specific expression of MADS-box genes and the function of MADS-box genes in other biological processes are still to be explored. Here, we report that OsMADS6 is highly expressed in flower and endosperm in Oryza sativa (rice). In addition to displaying a homeotic organ identity phenotype in all the four whorls of the flowers, the endosperm development is severely affected in its mutant. At least 32% of the seeds lacked starch filling and aborted. For seeds that have starch filling and develop to maturity, the starch content is reduced by at least 13%. In addition, the seed shape changes from elliptical to roundish, and the protein content increases from 12.1 to 15.0% (P < 0.05). Further investigation shows that ADP-glucose pyrophosphorylase genes, encoding the rate-limiting step enzyme in the starch synthesis pathway, are subject to the regulation of OsMADS6. Chromatin immunoprecipitation (ChIP)-PCR analyses on the chromatin of the OsMADS6 gene find that H3K27 is trimethylated in tissues where OsMADS6 is silenced, and that H3K36 is trimethylated in tissues where OsMADS6 is highly activated. Point mutation analysis reveals that leucine at position 83 is critical to OsMADS6 function.
DOI:10.1073/pnas.1219776110URLPMID:23236132 [本文引用: 1]
Grain size and shape are important components determining rice grain yield, and they are controlled by quantitative trait loci (QTLs). Here, we report the cloning and functional characterization of a major grain length QTL, qGL3, which encodes a putative protein phosphatase with Kelch-like repeat domain (OsPPKL1). We found a rare allele qgl3 that leads to a long grain phenotype by an aspartate-to-glutamate transition in a conserved AVLDT motif of the second Kelch domain in OsPPKL1. The rice genome has other two OsPPKL1 homologs, OsPPKL2 and OsPPKL3. Transgenic studies showed that OsPPKL1 and OsPPKL3 function as negative regulators of grain length, whereas OsPPKL2 as a positive regulator. The Kelch domains are essential for the OsPPKL1 biological function. Field trials showed that the application of the qgl3 allele could significantly increase grain yield in both inbred and hybrid rice varieties, due to its favorable effect on grain length, filling, and weight.
DOI:10.1073/pnas.1902321116URLPMID:31320586 [本文引用: 1]
Grain size is a key factor for determining grain yield in crops and is a target trait for both domestication and breeding, yet the mechanisms underlying the regulation of grain size are largely unclear. Here we show that the grain size and yield of rice (Oryza sativa) is positively regulated by ROP GTPase (Rho-like GTPase from plants), a versatile molecular switch modulating plant growth, development, and responses to the environment. Overexpression of rice OsRac1ROP not only increases cell numbers, resulting in a larger spikelet hull, but also accelerates grain filling rate, causing greater grain width and weight. As a result, OsRac1 overexpression improves grain yield in O. sativa by nearly 16%. In contrast, down-regulation or deletion of OsRac1 causes the opposite effects. RNA-seq and cell cycle analyses suggest that OsRac1 promotes cell division. Interestingly, OsRac1 interacts with and regulates the phosphorylation level of OsMAPK6, which is known to regulate cell division and grain size in rice. Thus, our findings suggest OsRac1 modulates rice grain size and yield by influencing cell division. This study provides insights into the molecular mechanisms underlying the control of rice grain size and suggests that OsRac1 could serve as a potential target gene for breeding high-yield crops.
DOI:10.1111/tpj.14329URLPMID:30912217 [本文引用: 1]
In rice (Oryza sativa L.), later flowering inferior spikelets (IS), which are located on proximal secondary branches, fill slowly and produce smaller and lighter grains than earlier flowering superior spikelets (SS). Many genes have been reported to be involved in poor grain filling of IS, however the underlying molecular mechanisms remain unclear. The present study determined that GF14f, a member of the 14-3-3 protein family, showed temporal and spatial differences in expression patterns between SS and IS. Using GF14f-RNAi plants, we observed that a reduction in GF14f expression in the endosperm resulted in a significant increase in both grain length and weight, which in turn improved grain yield. Furthermore, pull-down assays indicated that GF14f interacts with enzymes that are involved in sucrose breakdown, starch synthesis, tricarboxylic acid (TCA) cycle and glycolysis. At the same time, an increase in the activity of sucrose synthase (SuSase), adenosine diphosphate-glucose pyrophosphorylase (AGPase), and starch synthase (StSase) was observed in the GF14f-RNAi grains. Comprehensive analysis of the proteome and metabolite profiling revealed that the abundance of proteins related to the TCA cycle, and glycolysis increased in the GF14f-RNAi grains together with several carbohydrate intermediates. These results suggested that GF14f negatively affected grain development and filling, and the observed higher abundance of the GF14f protein in IS compared with SS may be responsible for poor IS grain filling. The study provides insights into the molecular mechanisms underlying poor grain filling of IS and suggests that GF14f could serve as a potential tool for improving rice grain filling.
DOI:10.1111/pbi.13009URLPMID:30183128 [本文引用: 2]
Rice grain filling rate contributes largely to grain productivity and accumulation of nutrients. MicroRNAs (miRNAs) are key regulators of development and physiology in plants and become a novel key target for engineering grain size and crop yield. However, there is little studies, so far, showing the miRNA regulation of grain filling and rice yield, in consequence. Here, we show that suppressed expression of rice miR1432 (STTM1432) significantly improves grain weight by enhancing grain filling rate and leads to an increase in overall grain yield up to 17.14% in a field trial. Molecular analysis identified rice Acyl-CoA thioesterase (OsACOT), which is conserved with ACOT13 in other species, as a major target of miR1432 by cleavage. Moreover, overexpression of miR1432-resistant form of OsACOT (OXmACOT) resembled the STTM1432 plants, that is, a large margin of an increase in grain weight up to 46.69% through improving the grain filling rate. Further study indicated that OsACOT was involved in biosynthesis of medium-chain fatty acids. In addition, RNA-seq based transcriptomic analyses of transgenic plants with altered expression of miR1432 demonstrated that downstream genes of miR1432-regulated network are involved in fatty acid metabolism and phytohormones biosynthesis and also overlap with the enrichment analysis of co-expressed genes of OsACOT, which is consistent with the increased levels of auxin and abscisic acid in STTM1432 and OXmACOT plants. Overall, miR1432-OsACOT module plays an important role in grain filling in rice, illustrating its capacity for engineering yield improvement in crops.
水稻重组自交群体灌浆速率的遗传分析
1
2012
... 近年来, 先后有3项研究涉及水稻GFR相关QTL的分析.
水稻籽粒灌浆的影响因子及其机制研究进展
1
2020
... 水稻(Oryza sativa)是我国最重要的粮食作物, 也是禾谷类植物分子生物学研究的模式物种.水稻经过开花、授粉和双受精之后, 子房发育为颖果, 随后进入籽粒灌浆(grain filling)时期.此时, 叶片等绿色组织光合作用产生和积累的同化物向颖果运输并转化, 最终颖果发育成为成熟籽粒.因此, 籽粒灌浆是稻米形成的关键阶段, 灌浆特性决定稻米的最终产量和品质.籽粒灌浆特性包括籽粒灌浆速率(grain-filling rate, GFR)、灌浆持续时间(grain-filling duration, GFD)以及与各种环境因子(温度、水分和氮肥等)的互作等(
The sucrose transporter gene family in rice
1
2003
... 蔗糖转运蛋白(sucrose transporter, SUT)基因是最早被发现与水稻籽粒灌浆相关的糖转运蛋白基因, 在水稻中有5个同源基因(
OsPK2 encodes a plastidic pyruvate kinase involved in rice endosperm starch synthesis, compound granule formation and grain filling
1
2018
... 最近的研究表明, 多个水稻糖酵解途径相关酶基因与GFR相关, 而糖酵解可以促进淀粉合成和代谢.OsPFP1编码糖酵解途径中的焦磷酸:果糖-6-磷酸1-磷酸转移酶(pyrophosphate:fructose-6-phosphate 1-phosphotransferase, PFP)的β亚基, 与3个α亚基共同形成异源四聚体, 催化果糖-6-磷酸与果糖-1,6-二磷酸间的可逆反应, 其突变导致籽粒造粉体和淀粉颗粒发育异常, 淀粉含量和GFR降低(
Control of grain size and rice yield by GL2-mediated brassinosteroid responses
2
2016
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
... ;
Pyrophosphate-fructose 6-phosphate 1-phosphotransferase (PFP1) regulates starch biosynthesis and seed development via heterotetramer formation in rice (Oryza sativa L.)
1
2020
... 最近的研究表明, 多个水稻糖酵解途径相关酶基因与GFR相关, 而糖酵解可以促进淀粉合成和代谢.OsPFP1编码糖酵解途径中的焦磷酸:果糖-6-磷酸1-磷酸转移酶(pyrophosphate:fructose-6-phosphate 1-phosphotransferase, PFP)的β亚基, 与3个α亚基共同形成异源四聚体, 催化果糖-6-磷酸与果糖-1,6-二磷酸间的可逆反应, 其突变导致籽粒造粉体和淀粉颗粒发育异常, 淀粉含量和GFR降低(
A missense mutation in Large Grain Size 1 increases grain size and enhances cold tolerance in rice
1
2019
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
Functional divergence of two duplicated Fertilization Independent Endosperm genes in rice with respect to seed development
1
2020
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
UDP-glucosyltransferase regulates grain size and abiotic stress tolerance associated with metabolic flux redirection in rice
1
2020
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
Pyrophosphate: fructose-6-phosphate 1-phosphotransferase (PFP) regulates carbon metabolism during grain filling in rice
1
2016
... 最近的研究表明, 多个水稻糖酵解途径相关酶基因与GFR相关, 而糖酵解可以促进淀粉合成和代谢.OsPFP1编码糖酵解途径中的焦磷酸:果糖-6-磷酸1-磷酸转移酶(pyrophosphate:fructose-6-phosphate 1-phosphotransferase, PFP)的β亚基, 与3个α亚基共同形成异源四聚体, 催化果糖-6-磷酸与果糖-1,6-二磷酸间的可逆反应, 其突变导致籽粒造粉体和淀粉颗粒发育异常, 淀粉含量和GFR降低(
Regulation of OsGRF4 by OsmiR396 controls grain size and yield in rice
1
2016
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
Impaired function of the tonoplast-localized sucrose transporter in rice, OsSUT2, limits the transport of vacuolar reserve sucrose and affects plant growth
1
2011
... 蔗糖转运蛋白(sucrose transporter, SUT)基因是最早被发现与水稻籽粒灌浆相关的糖转运蛋白基因, 在水稻中有5个同源基因(
Coexpression analysis identifies Rice Starch Regulator 1, a rice AP2/EREBP family transcription factor, as a novel rice starch biosynthesis regulator
1
2010
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
Rice qGL3/OsPPKL1 functions with the GSK3/SHAGGY-like kinase OsGSK3 to modulate brassinosteroid signaling
1
2019
... 目前至少发现3个粒型相关QTLs负调控GFRs, 分别为GW2、qGL3/GL3.1和GL7/GW7.控制粒宽和粒厚的GW2编码1个RING型E3泛素连接酶, 参与泛素化蛋白降解, 其功能缺失性等位基因可使颖壳细胞数目增加、GFR升高(
Cell wall invertase in developing rice caryopsis: molecular cloning of OsCIN1 and analysis of its expression in relation to its role in grain filling
1
2002
... 水稻籽粒的主要内含物是淀粉, 因此糖类代谢和运输在籽粒灌浆过程中至关重要.目前, 在已报道的水稻GFR相关基因中, 相当一部分是糖类代谢酶相关基因.光合作用产生的蔗糖需要转化为己糖磷酸酯才能进入籽粒细胞, 细胞壁转化酶(cell-wall invertase, CIN)在此过程中发挥至关重要的作用.CIN作为一类定位于细胞壁的蔗糖酶, 可将质外体中的蔗糖催化水解为葡萄糖和果糖(
A rare allele of GS2 enhances grain size and grain yield in rice
2
2015
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
... )、光合作用相关基因以及BR信号途径相关基因的表达(
Mitochondria-associated pyruvate kinase complexes regulate grain filling in rice
2
2020
... 最近的研究表明, 多个水稻糖酵解途径相关酶基因与GFR相关, 而糖酵解可以促进淀粉合成和代谢.OsPFP1编码糖酵解途径中的焦磷酸:果糖-6-磷酸1-磷酸转移酶(pyrophosphate:fructose-6-phosphate 1-phosphotransferase, PFP)的β亚基, 与3个α亚基共同形成异源四聚体, 催化果糖-6-磷酸与果糖-1,6-二磷酸间的可逆反应, 其突变导致籽粒造粉体和淀粉颗粒发育异常, 淀粉含量和GFR降低(
... 突变体的叶片中会发生蔗糖和淀粉积累, 说明OsPK3还影响蔗糖从源到库的转运和卸载(
2020b). Nondestructive 3D image analysis pipeline to extract rice grain traits using X-ray computed tomography
2
2020
... 水稻(Oryza sativa)是我国最重要的粮食作物, 也是禾谷类植物分子生物学研究的模式物种.水稻经过开花、授粉和双受精之后, 子房发育为颖果, 随后进入籽粒灌浆(grain filling)时期.此时, 叶片等绿色组织光合作用产生和积累的同化物向颖果运输并转化, 最终颖果发育成为成熟籽粒.因此, 籽粒灌浆是稻米形成的关键阶段, 灌浆特性决定稻米的最终产量和品质.籽粒灌浆特性包括籽粒灌浆速率(grain-filling rate, GFR)、灌浆持续时间(grain-filling duration, GFD)以及与各种环境因子(温度、水分和氮肥等)的互作等(
... GFR是重要的农艺性状和复杂的数量性状, 对GFR调控基因和优异等位变异进行挖掘和研究, 有助于实现水稻快速灌浆特性的精准育种, 从而提升水稻的产量和品质.目前, 关于GFR遗传分析的研究才刚刚起步, 对于GFR的分子调控机制和网络的认识还非常有限, 对GFR等灌浆相关特性和性状的分子遗传机制进行解析将是水稻等农作物研究领域的热点和突破点.随着显微CT等表型组学相关技术运用于籽粒灌浆研究(
Antisense expression of a rice sucrose transporter OsSUT1 in rice (Oryza sativa L.)
2
2001
... 蔗糖转运蛋白(sucrose transporter, SUT)基因是最早被发现与水稻籽粒灌浆相关的糖转运蛋白基因, 在水稻中有5个同源基因(
... 主要在灌浆颖果的糊粉层表达, 抑制该基因的表达导致严重的灌浆缺陷, 表明GFR可能降低, 但是叶片的光合作用不受影响, 其可能负责将蔗糖从叶片质外体转运到灌浆籽粒基部的韧皮部(
Loss of function of the IAA-glucose hydrolase gene TGW6 enhances rice grain weight and increases yield
1
2013
... 已克隆的2个粒重相关QTLs (TGW6和GW6a)也影响GFR.TGW6编码吲哚乙酸-葡萄糖水解酶, 通过控制吲哚乙酸供应影响胚乳合胞体阶段到细胞化阶段的转变, 从而控制胚乳细胞的数目和籽粒长度, 而功能缺失性等位基因导致粒重和粒长增加、GFR升高; TGW6不仅直接调控胚乳长度, 还间接参与从源到库的碳水化合物运输(
Association between grain filling rate and duration and yield components in rice
1
1979
... 水稻(Oryza sativa)是我国最重要的粮食作物, 也是禾谷类植物分子生物学研究的模式物种.水稻经过开花、授粉和双受精之后, 子房发育为颖果, 随后进入籽粒灌浆(grain filling)时期.此时, 叶片等绿色组织光合作用产生和积累的同化物向颖果运输并转化, 最终颖果发育成为成熟籽粒.因此, 籽粒灌浆是稻米形成的关键阶段, 灌浆特性决定稻米的最终产量和品质.籽粒灌浆特性包括籽粒灌浆速率(grain-filling rate, GFR)、灌浆持续时间(grain-filling duration, GFD)以及与各种环境因子(温度、水分和氮肥等)的互作等(
Inter-relationships amongst grain characteristics, grain-filling parameters and rice (Oryza sativa L.) milling quality
1
2001
... 水稻(Oryza sativa)是我国最重要的粮食作物, 也是禾谷类植物分子生物学研究的模式物种.水稻经过开花、授粉和双受精之后, 子房发育为颖果, 随后进入籽粒灌浆(grain filling)时期.此时, 叶片等绿色组织光合作用产生和积累的同化物向颖果运输并转化, 最终颖果发育成为成熟籽粒.因此, 籽粒灌浆是稻米形成的关键阶段, 灌浆特性决定稻米的最终产量和品质.籽粒灌浆特性包括籽粒灌浆速率(grain-filling rate, GFR)、灌浆持续时间(grain-filling duration, GFD)以及与各种环境因子(温度、水分和氮肥等)的互作等(
Compensation and interaction between RISBZ1 and RPBF during grain filling in rice
1
2009
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
Modulating plant growth-metabolism coordination for sustainable agriculture
1
2018
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
The OsmiR396c- OsGRF4-OsGIF1 regulatory module determines grain size and yield in rice
1
2016
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
OsFIE2 plays an essential role in the regulation of rice vegetative and reproductive development
1
2014
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
Natural variation in GS5 plays an important role in regulating grain size and yield in rice
1
2011
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
Time-course association mapping of the grain-filling rate in rice (Oryza sativa L.)
1
2015
... 近年来, 先后有3项研究涉及水稻GFR相关QTL的分析.
Favorable alleles of GRAIN-FILLING RATE 1 increase the grain-filling rate and yield of rice
4
2019
... 水稻(Oryza sativa)是我国最重要的粮食作物, 也是禾谷类植物分子生物学研究的模式物种.水稻经过开花、授粉和双受精之后, 子房发育为颖果, 随后进入籽粒灌浆(grain filling)时期.此时, 叶片等绿色组织光合作用产生和积累的同化物向颖果运输并转化, 最终颖果发育成为成熟籽粒.因此, 籽粒灌浆是稻米形成的关键阶段, 灌浆特性决定稻米的最终产量和品质.籽粒灌浆特性包括籽粒灌浆速率(grain-filling rate, GFR)、灌浆持续时间(grain-filling duration, GFD)以及与各种环境因子(温度、水分和氮肥等)的互作等(
... 目前, 我国多数水稻品种GFR较低, 快速灌浆的优良水稻种质比较缺乏, 可供育种利用的相关优异基因资源非常有限, 严重制约了水稻产量和品质的进一步提高(
... 近年来, 先后有3项研究涉及水稻GFR相关QTL的分析.
... 的表达, 使胚乳和剑叶中的蔗糖、葡萄糖及果糖含量增加(
Polycomb protein OsFIE2 affects plant height and grain yield in rice
1
2016
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
Essential role of sugar transporter OsSWEET11 during the early stage of rice grain filling
1
2017
... 蔗糖转运蛋白(sucrose transporter, SUT)基因是最早被发现与水稻籽粒灌浆相关的糖转运蛋白基因, 在水稻中有5个同源基因(
Involvement of rice polycomb protein OsFIE2 in plant growth and seed size
1
2012
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
Quantitative trait loci for nonstructural carbohydrate accumulation in leaf sheaths and culms of rice (Oryza sativa L.) and their effects on grain filling
1
2002
... 跟粒型和粒重一样, GFR也是复杂的数量性状, 对其进行QTL分析是鉴定育种可用的优异等位基因的有效策略.由于对GFR的测定费时费力, 水稻GFR相关QTL的研究相对缺乏, 对其遗传调控位点及分子机制所知甚少.由于水稻茎秆和叶鞘是源组织, 其中储存的非结构碳水化合物对于灌浆初期胚乳的发育非常重要(
Polycomb group gene OsFIE2 regulates rice (Oryza sativa) seed development and grain filling via a mechanism distinct from Arabidopsis
1
2013
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
A rice functional transcriptional activator, RISBZ1, responsible for endosperm-specific expression of storage protein genes through GCN4 motif
1
2001
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
FLOURY ENDOSPERM 6 encodes a CBM48 domain-containing protein involved in compound granule formation and starch synthesis in rice endosperm
1
2014
... 水稻籽粒的主要内含物是淀粉, 因此糖类代谢和运输在籽粒灌浆过程中至关重要.目前, 在已报道的水稻GFR相关基因中, 相当一部分是糖类代谢酶相关基因.光合作用产生的蔗糖需要转化为己糖磷酸酯才能进入籽粒细胞, 细胞壁转化酶(cell-wall invertase, CIN)在此过程中发挥至关重要的作用.CIN作为一类定位于细胞壁的蔗糖酶, 可将质外体中的蔗糖催化水解为葡萄糖和果糖(
Characterization and expression patterns of microRNAs involved in rice grain filling
1
2013
... microRNA通过介导靶基因信使RNA的切割和降解, 在转录后水平调节靶基因的表达.microRNA在水稻籽粒灌浆过程中发挥重要的调节作用, 推测多个microRNA通过调节同化物代谢、基因转录调控和植物激素稳态等相关基因的表达而影响籽粒灌浆(
Differentially expressed microRNA cohorts in seed development may contribute to poor grain filling of inferior spikelets in rice
1
2014
... microRNA通过介导靶基因信使RNA的切割和降解, 在转录后水平调节靶基因的表达.microRNA在水稻籽粒灌浆过程中发挥重要的调节作用, 推测多个microRNA通过调节同化物代谢、基因转录调控和植物激素稳态等相关基因的表达而影响籽粒灌浆(
The novel quantitative trait locus GL3.1 controls rice grain size and yield by regulating Cyclin-T1;3
2
2012
... 目前至少发现3个粒型相关QTLs负调控GFRs, 分别为GW2、qGL3/GL3.1和GL7/GW7.控制粒宽和粒厚的GW2编码1个RING型E3泛素连接酶, 参与泛素化蛋白降解, 其功能缺失性等位基因可使颖壳细胞数目增加、GFR升高(
... ).qGL3/GL3.1通过调控细胞周期蛋白Cyclin- T1; 3去磷酸化影响细胞分裂(
SALT-RESPONSIVE ERF 1 is a negative regulator of grain filling and gibberellin-mediated seedling establishment in rice
1
2014
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
Involvement of the sucrose transporter, OsSUT1, in the long-distance pathway for assimilate transport in rice
1
2007
... 蔗糖转运蛋白(sucrose transporter, SUT)基因是最早被发现与水稻籽粒灌浆相关的糖转运蛋白基因, 在水稻中有5个同源基因(
Antisense suppression of the rice transporter gene, OsSUT1, leads to impaired grain filling and germination but does not affect photosynthesis
1
2002
... 蔗糖转运蛋白(sucrose transporter, SUT)基因是最早被发现与水稻籽粒灌浆相关的糖转运蛋白基因, 在水稻中有5个同源基因(
Ubiquitin Specific Protease 15 has an important role in regulating grain width and size in rice
1
2019
... 目前至少发现3个粒型相关QTLs负调控GFRs, 分别为GW2、qGL3/GL3.1和GL7/GW7.控制粒宽和粒厚的GW2编码1个RING型E3泛素连接酶, 参与泛素化蛋白降解, 其功能缺失性等位基因可使颖壳细胞数目增加、GFR升高(
OsSPL13 controls grain size in cultivated rice
1
2016
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
A QTL for rice grain width and weight encodes a previously unknown RING-type E3 ubiquitin ligase
1
2007
... 目前至少发现3个粒型相关QTLs负调控GFRs, 分别为GW2、qGL3/GL3.1和GL7/GW7.控制粒宽和粒厚的GW2编码1个RING型E3泛素连接酶, 参与泛素化蛋白降解, 其功能缺失性等位基因可使颖壳细胞数目增加、GFR升高(
Rare allele of a previously unidentified histone H4 acetyltransferase enhances grain weight, yield, and plant biomass in rice
1
2015
... 已克隆的2个粒重相关QTLs (TGW6和GW6a)也影响GFR.TGW6编码吲哚乙酸-葡萄糖水解酶, 通过控制吲哚乙酸供应影响胚乳合胞体阶段到细胞化阶段的转变, 从而控制胚乳细胞的数目和籽粒长度, 而功能缺失性等位基因导致粒重和粒长增加、GFR升高; TGW6不仅直接调控胚乳长度, 还间接参与从源到库的碳水化合物运输(
Seed filling in domesticated maize and rice depends on SWEET-mediated hexose transport
1
2015
... 蔗糖转运蛋白(sucrose transporter, SUT)基因是最早被发现与水稻籽粒灌浆相关的糖转运蛋白基因, 在水稻中有5个同源基因(
The sucrose-cleaving enzymes of plants are crucial for development, growth and carbon partitioning
1
1999
... 水稻籽粒的主要内含物是淀粉, 因此糖类代谢和运输在籽粒灌浆过程中至关重要.目前, 在已报道的水稻GFR相关基因中, 相当一部分是糖类代谢酶相关基因.光合作用产生的蔗糖需要转化为己糖磷酸酯才能进入籽粒细胞, 细胞壁转化酶(cell-wall invertase, CIN)在此过程中发挥至关重要的作用.CIN作为一类定位于细胞壁的蔗糖酶, 可将质外体中的蔗糖催化水解为葡萄糖和果糖(
OsGRF4 controls grain shape, panicle length and seed shattering in rice
1
2016
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
Time- related mapping of quantitative trait loci controlling grain- filling in rice (Oryza sativa L.)
1
2005
... 跟粒型和粒重一样, GFR也是复杂的数量性状, 对其进行QTL分析是鉴定育种可用的优异等位基因的有效策略.由于对GFR的测定费时费力, 水稻GFR相关QTL的研究相对缺乏, 对其遗传调控位点及分子机制所知甚少.由于水稻茎秆和叶鞘是源组织, 其中储存的非结构碳水化合物对于灌浆初期胚乳的发育非常重要(
Filling percentage of rice spikelets as affected by availability of non- structural carbohydrates at the initial phase of grain filling
1
1996
... 跟粒型和粒重一样, GFR也是复杂的数量性状, 对其进行QTL分析是鉴定育种可用的优异等位基因的有效策略.由于对GFR的测定费时费力, 水稻GFR相关QTL的研究相对缺乏, 对其遗传调控位点及分子机制所知甚少.由于水稻茎秆和叶鞘是源组织, 其中储存的非结构碳水化合物对于灌浆初期胚乳的发育非常重要(
Control of rice grain-filling and yield by a gene with a potential signature of domestication
2
2008
... 水稻籽粒的主要内含物是淀粉, 因此糖类代谢和运输在籽粒灌浆过程中至关重要.目前, 在已报道的水稻GFR相关基因中, 相当一部分是糖类代谢酶相关基因.光合作用产生的蔗糖需要转化为己糖磷酸酯才能进入籽粒细胞, 细胞壁转化酶(cell-wall invertase, CIN)在此过程中发挥至关重要的作用.CIN作为一类定位于细胞壁的蔗糖酶, 可将质外体中的蔗糖催化水解为葡萄糖和果糖(
... 等位基因具有广泛的时空表达; 将后者导入栽培稻中, 会显著降低栽培稻的GFR (
Duplication and independent selection of cell-wall invertase genes GIF1 and OsCIN1 during rice evolution and domestication
1
2010
... 水稻籽粒的主要内含物是淀粉, 因此糖类代谢和运输在籽粒灌浆过程中至关重要.目前, 在已报道的水稻GFR相关基因中, 相当一部分是糖类代谢酶相关基因.光合作用产生的蔗糖需要转化为己糖磷酸酯才能进入籽粒细胞, 细胞壁转化酶(cell-wall invertase, CIN)在此过程中发挥至关重要的作用.CIN作为一类定位于细胞壁的蔗糖酶, 可将质外体中的蔗糖催化水解为葡萄糖和果糖(
OsbZIP58, a basic leucine zipper transcription factor, regulates starch biosynthesis in rice endosperm
1
2013
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
The OsSPL16-GW7 regulatory module determines grain shape and simultaneously improves rice yield and grain quality
1
2015
... 目前至少发现3个粒型相关QTLs负调控GFRs, 分别为GW2、qGL3/GL3.1和GL7/GW7.控制粒宽和粒厚的GW2编码1个RING型E3泛素连接酶, 参与泛素化蛋白降解, 其功能缺失性等位基因可使颖壳细胞数目增加、GFR升高(
Control of grain size, shape and quality by OsSPL16 in rice
1
2012
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
Copy number variation at the GL7 locus contributes to grain size diversity in rice
1
2015
... 目前至少发现3个粒型相关QTLs负调控GFRs, 分别为GW2、qGL3/GL3.1和GL7/GW7.控制粒宽和粒厚的GW2编码1个RING型E3泛素连接酶, 参与泛素化蛋白降解, 其功能缺失性等位基因可使颖壳细胞数目增加、GFR升高(
GRAIN INCOMPLETE FILLING 2 regulates grain filling and starch synthesis during rice caryopsis development
2
2017
... 水稻籽粒的主要内含物是淀粉, 因此糖类代谢和运输在籽粒灌浆过程中至关重要.目前, 在已报道的水稻GFR相关基因中, 相当一部分是糖类代谢酶相关基因.光合作用产生的蔗糖需要转化为己糖磷酸酯才能进入籽粒细胞, 细胞壁转化酶(cell-wall invertase, CIN)在此过程中发挥至关重要的作用.CIN作为一类定位于细胞壁的蔗糖酶, 可将质外体中的蔗糖催化水解为葡萄糖和果糖(
... ).AGPase是淀粉合成的限速酶, 催化1-磷酸葡萄糖与ATP反应生成腺苷二磷酸葡萄糖(淀粉合成的前体), 其突变会影响籽粒中淀粉的合成, 导致GFR降低(
The QTL GNP1 encodes GA20ox1, which increases grain number and yield by increasing cytokinin activity in rice panicle meristems
2
2016
... GNP1 (Grain Number per Panicle 1)是调控水稻穗粒数的QTL, 其编码1个赤霉素(GA)氧化酶OsGA- 20ox1, 催化GA生物合成的倒数第2步反应(
... 的表达, 降低2种GA (GA1和GA3)的积累, 最终提高籽粒数目和产量, 但同时降低结实率、穗数、粒重以及GFR (
Rice transcription factor OsDOF11 modulates sugar transport by promoting expression of Sucrose Transporter and SWEET genes
1
2018
... 此外, 水稻bZIP (basic leucine zipper)转录因子家族基因RISBZ1 (又名OsbZIP58)、DOF (DNA binding with one finger)转录因子家族基因RPBF和OsDOF11、AP2/ERF转录因子家族基因SERF1和RSR1都参与调控灌浆相关基因的转录表达, 但其对GFR的具体作用还有待深入研究.RISBZ1与RPBF共同形成转录激活子正调控籽粒贮藏蛋白基因的表达(
NF-YC12 is a key multi-functional regulator of accumulation of seed storage substances in rice
2
2019
... 在水稻籽粒灌浆过程中, 糖类等物质代谢与运输以及胚乳发育受到转录水平、转录后水平、翻译水平和翻译后水平等多级复杂调控.目前研究较多的是基因转录水平上的籽粒灌浆调控机制, 已发现数个相关转录因子.MADS-box (MCM1、Agamous、Deficiens和SRF-box)转录因子因其包含高度保守的MADS结构域而得名, 多数参与花器官形态建成等发育过程.水稻MADS-box转录因子基因OsMADS6可调控多个AGPase基因(OsAGPS1、OsAGPL2和OsAGPL3)的表达, 其突变体籽粒灌浆发生严重缺陷, 淀粉积累减少(
... 的启动子结合, 直接调控后者的转录(
Differential expression of GS5 regulates grain size in rice
2
2015
... 根据作物产量生理的源-库-流理论(source-sink-translocation theory), 更大的颖壳意味着更大的库容量, 其与GFR存在一定的相关性.目前发现已克隆的一些水稻粒型相关数量性状位点(quantitative trait locus, QTLs)也影响GFR.其中, 至少有5个粒型相关QTLs可能正调控GFR, 分别是GS5、GS2/GL2/GLW2、GW8、GLW7和GSA1.编码丝氨酸羧肽酶的GS5启动子区域2个SNP影响该基因在幼穗中的表达, GS5表达增强可使颖壳增宽、GFR升高(
... ).GS5通过竞争性结合油菜素内酯(brassinosteroid, BR)相关受体激酶OsBAK1-7的富含亮氨酸重复结构域, 抑制后者与膜类固醇结合蛋白OsMSBP1的互作, 进而阻止OsBAK1-7的胞吞作用而影响BR信号(
Rice aleurone layer specific OsNF-YB1 regulates grain filling and endosperm development by interacting with an ERF transcription factor
2
2016
... 在水稻籽粒灌浆过程中, 糖类等物质代谢与运输以及胚乳发育受到转录水平、转录后水平、翻译水平和翻译后水平等多级复杂调控.目前研究较多的是基因转录水平上的籽粒灌浆调控机制, 已发现数个相关转录因子.MADS-box (MCM1、Agamous、Deficiens和SRF-box)转录因子因其包含高度保守的MADS结构域而得名, 多数参与花器官形态建成等发育过程.水稻MADS-box转录因子基因OsMADS6可调控多个AGPase基因(OsAGPS1、OsAGPL2和OsAGPL3)的表达, 其突变体籽粒灌浆发生严重缺陷, 淀粉积累减少(
... (
SWEET11 and 15 as key players in seed filling in rice
1
2018
... 蔗糖转运蛋白(sucrose transporter, SUT)基因是最早被发现与水稻籽粒灌浆相关的糖转运蛋白基因, 在水稻中有5个同源基因(
Grain filling of cereals under soil drying
1
2006
... 水稻(Oryza sativa)是我国最重要的粮食作物, 也是禾谷类植物分子生物学研究的模式物种.水稻经过开花、授粉和双受精之后, 子房发育为颖果, 随后进入籽粒灌浆(grain filling)时期.此时, 叶片等绿色组织光合作用产生和积累的同化物向颖果运输并转化, 最终颖果发育成为成熟籽粒.因此, 籽粒灌浆是稻米形成的关键阶段, 灌浆特性决定稻米的最终产量和品质.籽粒灌浆特性包括籽粒灌浆速率(grain-filling rate, GFR)、灌浆持续时间(grain-filling duration, GFD)以及与各种环境因子(温度、水分和氮肥等)的互作等(
Grain-filling problem in ‘super’ rice
2
2010
... 水稻(Oryza sativa)是我国最重要的粮食作物, 也是禾谷类植物分子生物学研究的模式物种.水稻经过开花、授粉和双受精之后, 子房发育为颖果, 随后进入籽粒灌浆(grain filling)时期.此时, 叶片等绿色组织光合作用产生和积累的同化物向颖果运输并转化, 最终颖果发育成为成熟籽粒.因此, 籽粒灌浆是稻米形成的关键阶段, 灌浆特性决定稻米的最终产量和品质.籽粒灌浆特性包括籽粒灌浆速率(grain-filling rate, GFR)、灌浆持续时间(grain-filling duration, GFD)以及与各种环境因子(温度、水分和氮肥等)的互作等(
... 目前, 我国多数水稻品种GFR较低, 快速灌浆的优良水稻种质比较缺乏, 可供育种利用的相关优异基因资源非常有限, 严重制约了水稻产量和品质的进一步提高(
Hormonal changes in the grains of rice subjected to water stress during grain filling
1
2001
... 目前, 我国多数水稻品种GFR较低, 快速灌浆的优良水稻种质比较缺乏, 可供育种利用的相关优异基因资源非常有限, 严重制约了水稻产量和品质的进一步提高(
Identification and expression analysis of microRNAs at the grain filling stage in rice (Oryza sativa L.) via deep sequencing
1
2013
... microRNA通过介导靶基因信使RNA的切割和降解, 在转录后水平调节靶基因的表达.microRNA在水稻籽粒灌浆过程中发挥重要的调节作用, 推测多个microRNA通过调节同化物代谢、基因转录调控和植物激素稳态等相关基因的表达而影响籽粒灌浆(
The MADS29 transcription factor regulates the degradation of the nucellus and the nucellar projection during rice seed development
1
2012
... 在水稻籽粒灌浆过程中, 糖类等物质代谢与运输以及胚乳发育受到转录水平、转录后水平、翻译水平和翻译后水平等多级复杂调控.目前研究较多的是基因转录水平上的籽粒灌浆调控机制, 已发现数个相关转录因子.MADS-box (MCM1、Agamous、Deficiens和SRF-box)转录因子因其包含高度保守的MADS结构域而得名, 多数参与花器官形态建成等发育过程.水稻MADS-box转录因子基因OsMADS6可调控多个AGPase基因(OsAGPS1、OsAGPL2和OsAGPL3)的表达, 其突变体籽粒灌浆发生严重缺陷, 淀粉积累减少(
Pleiotropic effect of GNP1 underlying grain number per panicle on sink, source and flow in rice
1
2020
... GNP1 (Grain Number per Panicle 1)是调控水稻穗粒数的QTL, 其编码1个赤霉素(GA)氧化酶OsGA- 20ox1, 催化GA生物合成的倒数第2步反应(
OsMADS6 plays an essential role in endosperm nutrient accumulation and is subject to epigenetic regulation in rice (Oryza sativa)
1
2010
... 在水稻籽粒灌浆过程中, 糖类等物质代谢与运输以及胚乳发育受到转录水平、转录后水平、翻译水平和翻译后水平等多级复杂调控.目前研究较多的是基因转录水平上的籽粒灌浆调控机制, 已发现数个相关转录因子.MADS-box (MCM1、Agamous、Deficiens和SRF-box)转录因子因其包含高度保守的MADS结构域而得名, 多数参与花器官形态建成等发育过程.水稻MADS-box转录因子基因OsMADS6可调控多个AGPase基因(OsAGPS1、OsAGPL2和OsAGPL3)的表达, 其突变体籽粒灌浆发生严重缺陷, 淀粉积累减少(
Rare allele of OsPPKL1 associated with grain length causes extra-large grain and a significant yield increase in rice
1
2012
... 目前至少发现3个粒型相关QTLs负调控GFRs, 分别为GW2、qGL3/GL3.1和GL7/GW7.控制粒宽和粒厚的GW2编码1个RING型E3泛素连接酶, 参与泛素化蛋白降解, 其功能缺失性等位基因可使颖壳细胞数目增加、GFR升高(
The Rho-family GTPase OsRac1 controls rice grain size and yield by regulating cell division
1
2019
... 研究发现, 编码Rho家族GTPase的水稻基因OsRac1在翻译后蛋白化学修饰水平上正调控GFR; 其负责丝裂原活化蛋白激酶OsMAPK6的磷酸化, 过表达该基因可以促进细胞分裂, 使籽粒增大、GFR升高, 而敲除该基因导致GFR降低(
The 14-3-3 protein GF14f negatively affects grain filling of inferior spikelets of rice (Oryza sativa L.)
1
2019
... 研究发现, 编码Rho家族GTPase的水稻基因OsRac1在翻译后蛋白化学修饰水平上正调控GFR; 其负责丝裂原活化蛋白激酶OsMAPK6的磷酸化, 过表达该基因可以促进细胞分裂, 使籽粒增大、GFR升高, 而敲除该基因导致GFR降低(
miR1432- OsACOT (Acyl-CoA thioesterase) module determines grain yield via enhancing grain filling rate in rice
2
2019
... microRNA通过介导靶基因信使RNA的切割和降解, 在转录后水平调节靶基因的表达.microRNA在水稻籽粒灌浆过程中发挥重要的调节作用, 推测多个microRNA通过调节同化物代谢、基因转录调控和植物激素稳态等相关基因的表达而影响籽粒灌浆(
... 同样可提高GFR (
