关键词:水稻; 侧根发育; 中柱鞘; 内皮层; 生长素; 光照 Rice Lateral Root Development and Its Impact Factors LIU Da-Tong, JING Yan-Ping, CHEN Jing-Jing, YU Xu-Run, WANG Zhong* College of Bioscience and Biotechnology, Yangzhou University / Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou 225009, China Fund: AbstractThe adventitious roots and primary roots of Nipponbare and Yangdao 6 were used to measure lateral root number and the growth increment by Image J software with scanning photograph. Morphological and structural changes of lateral root primodia were observed by applying Spurr resin embedding and semi-thin sectioning, and light microscopy. Impacts of the lateral root emergence on the parent root structure was observed by fluorescence microscopy and scanning electron microscopy. Treatments with plant hormones, metal ions, illumination, and cutting off shoots or root tips were set up to analyse their influence on lateral root development. Results showed that rice lateral root initiation occurred from the pericycle. The endodermis also participated in the lateral root primodia formation and played protective as well as assistant roles in the process. The outward growth of lateral root primordia was realized by cell divisions of apical meristem and cell elongation at the base area. The cortex and epidermis structures of parent roots were also altered during the process of lateral root emergence. Exogenous IAA promoted the occurrence of lateral roots, but its high concentrations inhibited lateral root emergence. The number of lateral roots and growth of primary roots were significantly decreased when shoots were cut off. The apical dominance of root was lost when root tips were cut off, so that the growth of lateral roots and secondary lateral roots was accelerated. Unilateral illumination induced the increase of lateral roots in the light side. Abscisic acid at low concentrations promoted the formation of lateral roots. The formation of lateral roots and growth of primary root were promoted by Ca2+, while mostly inhibited by EDTA. The growth tendency of both adventitious roots and primary roots responsive to the treatments was basically consistent.
Keyword:Rice; Lateral root development; Pericycle; Endodermis; IAA; Illumination Show Figures Show Figures
图1 水稻侧根发育的过程A: 半薄切片; I~VI: 示侧根形态建成, E: 内皮层; P: 中柱鞘; S: 中柱; Ct: 皮层; LRP: 侧根原基; I~IV, bar=20 μm; V, VI, bar=50 μm。B: 荧光显微观察; I: 侧根露出前的母根表皮, 箭头指示侧根原基; II, III: 母根表皮上出现缝隙, 箭头指示侧根原基和母根表皮间的缝隙; IV: 侧根露出后母根表皮,箭头指示表皮与侧根的巨大间隙, bar=100 μm。C: 扫描电镜下侧根和母根表皮; 箭头指示破损外翘的表皮, bar=50 μm。D: 扫描电镜下的侧根断面和母根结构; 箭头指示破损的表皮、皮层和破损间隙, bar=50 μm。Fig. 1 Lateral root development of riceA: I-VI: process of lateral root formation shown by semi-thin slices. E: endodermis; P: pericycle; S: stele; Ct: cortex. LRP: lateral root primordia. I-IV, bar=20 μm; V, VI, bar=50 μm. B: I: epidermis of parent root before lateral root emergence, arrows indicate the primordia. II, III: cracks appeared on the parent root, arrows indicate the primodias and the gap on the epidermis. IV: epidermis of parent root after lateral root emergence, arrows indicate the gap between. bar =100 μm. C, D: photographs about lateral roots and epidermis of parent root under SEM, arrows indicate the broken epidermis, cortex and the gaps, bar=50 μm.
图2 切除芽或根尖对侧根数和主根生长的影响A: 切除芽或根尖对侧根数和生长量的影响, ** P < 0.01; B: 对照, 不做任何处理; C: 切除芽; D: 切除根尖, 方框中为局部放大部分。Fig. 2 Impact of cutting off shoot and root tips on lateral root number and primary root growthA: comparison of the lateral root number and growth, ** P < 0.01; B: control, without any treatment; C: seedling cut off shoot; D: seedling cut off root tip, and the part in block is the amplified, bar=1 cm.
图3 光照引起向光侧的侧根发生增多A: 单侧光照促进大田苗不定根向光侧的侧根发生, bar=1 cm; B: 种子根弯曲部位半薄切片, bar=100 μm; C: 向光侧发生的侧根原基放大, bar=50 μm; D: 黑暗下生长的根尖NBT染色, bar=100 μm; E: 根尖弯曲部位NBT染色, bar=100 μm。Fig. 3 Occurrence of lateral roots increased in the irradiated sideA: occurrence of lateral roots promoted in the irradiated side of adventitious roots, bar=1 cm; B: semi-thin slice in the curve part of primary root, bar=100 μm; C: amplification of a part of Pig. A for primordia in the irradiated side, bar=50 μm; D: NBT staining of root tips grown in the dark; E: NBT staining of the curve part; bar=100 μm in D and E.
图4 水稻侧根数和主根生长量随IAA、TIBA、ABA、Ca2+和EDTA浓度的变化Nip AR: 日本晴不定根; Yang 6 AR: 扬稻6号不定根; Nip PR: 日本晴种子根; Yang 6 PR: 扬稻6号种子根。Fig. 4 Dynamic changes of lateral roots number and growth increment of primary roots with the concentration gradient of IAA, TIBA, ABA, Ca2+, and EDTANip AR: adventitious root of Nipponbare; Yang 6 AR: adventitious root of Yangdao 6; Nip PR: primary root of Nipponbare; Yang 6 PR: primary root of Yangdao 6.
图5 中柱鞘和内皮层在水稻侧根原基建成过程中的形态变化A: 中柱鞘中的PFCs和生长素峰; B: 正对着PFCs的相邻内皮层细胞在高浓度生长素刺激下的形态变化; C, D: PFCs和内皮层细胞各自进行分裂形成的两部分侧根原基结构; E: 发育出基部输导组织和顶端生长点的成熟侧根原基。Fig. 5 Morphological changes of pericycle and endodermis during LPR formationA: PFCs in pericycle and the auxin peak; B: stimulated by the high concentration of auxin in PFCs, morphological changes occurred in the adjacent endodermis; C, D: PFCs and endodermis cells divided respectively and formed two parts of lateral root primordia; E: mature lateral root primordia with apical meristem and basal conducting tissues.
ChhunT, TaketaS, TsurumiS, IchiiM. The effects of auxin on lateral root initiation and root gravitropism in a lateral rootless mutant Lrt1 of rice (Oryza sativa L. ). , 2003, 39: 161-170[本文引用:1][JCR: 1.67]
[9]
ChenX, ShiJ, HaoX, LiuH, ShiJ, WuY, WuZ, ChenM, WuP, MaoC. OsORC3 is required for lateral root development in rice. , 2013, 74: 339-350[本文引用:1][JCR: 6.582]
[10]
王忠, 李卫芳, 顾蕴洁, 陈刚, 石火英, 高煜珠. 水稻胚乳的发育及其养分输入的途径. , 1995, 21: 520-527WangZ, LiW F, GuY J, ChenG, ShiH Y, GaoY Z. Development of rice endosperm and the pathway of nutrients entering the endosperm. , 1995, 21: 520-527 (in Chinese with English abstract)[本文引用:1][CJCR: 1.667]
CaseroP, CasimiroI, Rodriguez-GallardoL, Martín-PartidoG, LloretP. Lateral root initiation by asymmetrical transverse divisions of pericycle cells in adventitious roots of Allium cepa. , 1993, 176: 138-144[本文引用:1][JCR: 2.855]
[13]
ParizotB, LaplazeL, RicaudL, Boucheron-DubuissonE, BayleV, BonkeM, DeSmet I, PoethigS R, HelariuttaY, HaseloffJ, ChriquiD, BeeckmanT, NussaumeL. Diarch symmetry of the vascular bundle in Arabidopsis root encompasses the pericycle and is reflected in distich lateral root initiation. , 2008, 146: 140-148[本文引用:1][JCR: 6.555]
[14]
PéretB, LarrieuA, BennettM J. Lateral root emergence: a difficult birth. , 2009, 60: 3637-3643[本文引用:2][JCR: 5.242]
[15]
LjungK, HullbA K, CelenzacJ, YamadadM, EstelledM, NormanlyeJ, Sand bergaG. Sites and regulation of auxin biosynthesis in Arabidopsis roots. , 2005, 17: 1090-1104[本文引用:2][JCR: 9.251]
[16]
MarchantA, BhaleraoR, CasimirocI, EklöfbJ, CaserocP J, BennettaM, Sand bergG. AUX1 promotes lateral root formation by facilitating indole-3-acetic acid distribution between sink and source tissues in the Arabidopsis seedling. , 2002, 14: 589-597[本文引用:1][JCR: 9.251]
[17]
LaskowskiM J, WilliamsM E, NusbaumH C, SussexI M. Formation of lateral root meristems is a two-stage process. , 1995, 121: 3303-3310[本文引用:1]
ChenC W, YangY W, LurH S, TsaiY G, ChangM C. A novel function of abscisic acid in the regulation of rice (Oryza sativa L. ) root growth and development. , 2006, 47: 1-13[本文引用:1][JCR: 4.134]
[23]
郭栋梁, 李玲. ABA对植物侧根发生的调节. , 2008, 37: 67-69GuoD L, LiL. ABA regulation of lateral root development in plants. , 2008, 37: 67-69 (in Chinese with English abstract)[本文引用:1][CJCR: 0.4945]
BaoF, ShenJ, BradyS R, MudayG K, AsamiT, YangZ B. Brassinosteroids interact with auxin to promote lateral root development in Arabidopsis. , 2004, 134: 1624-1631[本文引用:1][JCR: 6.555]
[26]
IvanchenkoM G, MudayG K, DubrovskyJ G. Ethylene-auxin interactions regulate lateral root initiation and emergence in Arabidopsis thaliana. , 2008, 55: 335-347[本文引用:1][JCR: 6.582]
[27]
NegiS, IvanchenkoM G, MudayG K. Ethylene regulates lateral root formation and auxin transport in Arabidopsis thaliana. , 2008, 55: 175-187[本文引用:1][JCR: 6.582]
[28]
江玲, 管晓春. Ca2+-CaM系统在生长素诱导莴苣侧根原基形成中的作用. , 2003, 26(1): 6-9JiangL, GuanX C. Role of Ca2+-CaM on lateral root primordium formation induced by auxins in lettuce seedlings. , 2003, 26(1): 6-9 (in Chinese with English abstract)[本文引用:1][CJCR: 0.916]
[29]
MoY, WangZ, QianS, GuY. Effect of indoleacetic acid (IAA) on the negative phototropism of rice root. , 2004, 11: 125-128[本文引用:1][CJCR: 0.3579]
[30]
WangZ, MoY, QianS, GuY. Negative phototropism of rice root and its influencing factors. , 2002, 45: 485-496[本文引用:1]
[31]
郭保卫. 水稻抛秧立苗机理及其调控. , 2010. pp1-10GuoB W. Mechanism of Seedling Stand ing and Establishment of Broadcasted Rice and Its Regulation. Master Dissertation of Yangzhou University, Yangzhou, China, 2010. pp1-10 (in Chinese with English abstract)[本文引用:1]
[32]
张洪程, 戴其根, 霍中洋, 许轲, 魏海燕. 中国抛秧稻作技术体系及其特征. , 2008, 41: 43-52ZhangH C, DaiQ G, HuoZ Y, XuK, WeiH Y. Cultivation technical system of rice seedling broadcasting and its characteristics. , 2008, 41: 43-52 (in Chinese with English abstract)[本文引用:1][CJCR: 1.889]
[33]
郭保卫, 陈厚存, 张春华, 魏海燕, 张洪程, 戴其根, 霍中洋, 许轲, 邢琳, 管文文, 黄幸福, 杨雄. 水稻抛栽秧立苗中的形态与生理变化. , 2010, 36: 1715-1724GuoB W, ChenH C, ZhangC H, WeiH Y, ZhangH C, DaiQ G, HuoZ Y, XuK, XingL, GuanW W, HuangX F, YangX. Morphological and physiological changes in seedling stand ing and establishment of broadcasted rice seedlings. , 2010, 36: 1715-1724 (in Chinese with English abstract)[本文引用:1][CJCR: 1.667]
[34]
SasidharanR, ChinnappaC C, StaalM, ElzengaJ, TheoM, YokoyamaR, NishitaniK, Voesenek L A C J, PierikR. Light qua-lity-mediated petiole elongation in Arabidopsis during shade avoidance involves cell wall modification by xyloglucan endotransglucosylase/hydrolases. , 2010, 154: 978-990[本文引用:1][JCR: 6.555]
[35]
Łukawska-KuźmaK, PodgórskaA, RychterA M. Plasma membrane-generated ROS and their possible contribution to leaf cell growth of cucumber (Cucumis sativus) MSC16 mitochondrial mutant. , 2012, 34: 721-730[本文引用:1][JCR: 1.305]
[36]
HeynoE, MaryV, SchopferP, Krieger-LiszkayA. Oxygen activation at the plasma membrane: relation between superoxide and hydroxyl radical production by isolated membranes. , 2011, 234: 35-45[本文引用:1][JCR: 3.347]
[37]
Krieger-LiszkayA, van de Zalm E, SchopferP. Production of reactive oxygen intermediates (O2?, H2O2, and OH) by maize roots and their role in wall loosening and elongation growth. , 2004, 136: 3114-3123[本文引用:1][JCR: 6.555]
[38]
RenewS, HeynoE, SchopferP, LiszkayA. Sensitive detection and localization of hydroxyl radical production in cucumber roots and Arabidopsis seedlings by spin trapping electron paramagnetic resonance spectroscopy. , 2005, 44: 342-347[本文引用:1][JCR: 6.582]
[39]
汪月霞, 王忠, 刘全军, 赵会杰, 顾蕴洁, 钱晓旦, 袁志良. cpt1基因与水稻根负向光性运动的关系. , 2009, 35: 1558-1561WangY X, WangZ, LiuQ J, ZhaoH J, GuY J, QianX D, YuanZ L. Relationship between cpt1 gene and the negative phototropism in rice roots. , 2009, 35: 1558-1561 (in Chinese with English abstract)[本文引用:1][CJCR: 1.667]