刘齐^,1, 梅延豪¹, 李琦¹, 马宏秀³, 武永军², 杨振超^,11西北农林科技大学园艺学院/农业农村部西北设施园艺工程重点实验室,陕西杨凌 712100
²西北农林科技大学生命学院,陕西杨凌712100
³杨凌凌宇现代农业研究院,陕西杨凌 712100

Effects of End of Day Far-Red Light on Growth, Histiocyte Morphology and Phytohormones Content of Pumpkin Seedlings

LIU Qi^,1, MEI YanHao¹, LI Qi¹, MA HongXiu³, WU YongJun², YANG ZhenChao^{,1 1}College of Horticulture, Northwest A&F University/Key Laboratory of Protected Horticultural Engineering in Northwestern China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi
²College of Sciences, Northwest A&F University, Yangling 712100, Shaanxi
³Lingyu Modern Agricultural Research Institute, Yangling 712100, Shaanxi

通讯作者: 杨振超,E-mail: yangzhenchao@nwafu.edu.cn

责任编辑: 赵伶俐
收稿日期:2020-03-14接受日期:2020-05-12网络出版日期:2020-10-16

基金资助:

国家重点研发计划.2018YFD0201205-2 陕西省农业厅农业科技创新集成推广项目.NYKJ-2018-YL22

Received:2020-03-14Accepted:2020-05-12Online:2020-10-16
作者简介 About authors
刘齐,E-mail: lq821798304@163.com。








摘要
【目的】研究暗期前短暂远红光处理对南瓜幼苗生长形态、组织细胞形态和相关激素水平的影响,为远红光在农业上的应用提供理论依据。【方法】以南瓜品种‘日本雪松’为试验材料,分别在暗期前给予2（T1）、4（T2）、6（T3）、8（T4）、10（T5）和12（T6）mmol·m^-2·d^-1的远红光处理,以无远红光处理为对照（CK）,测定植株生长形态下胚轴细胞形态以及生长素（IAA）、玉米素（ZT）、赤霉素（GA₃）与油菜素内酯（BR）含量。【结果】在暗期短时外施远红光能显著提高南瓜幼苗下胚轴长度和株高,对植株茎粗,地上、地下部干/鲜重无显著影响;2、4、6、8、10和12 mmol·m^-2·d^-1远红光处理的下胚轴薄壁细胞轴向长度分别比CK显著增加34.6%、20.7%、31.3%、25.6%、32.8%和20.9%;下胚轴厚角组织厚度分别比CK显著增加19.6%、22.4%、21.2%、23.9%、19.6%和28%;经暗期前远红光处理后,南瓜幼苗根中生长素（IAA）含量,下胚轴中生长素（IAA）、赤霉素（GA₃）、玉米素（ZT）含量,子叶中生长素（IAA)、赤霉素（GA₃）、油菜素内酯（BR）含量以及真叶中生长素（IAA）与油菜素内酯（BR）含量均得到显著提高。【结论】暗期前短时远红光处理可能通过提高激素含量,进而改变细胞形态,促进下胚轴伸长生长。
关键词： 远红光;南瓜幼苗;下胚轴;细胞形态;激素;远红光调控

Abstract
【Objective】This study was aimed to understand the effects of growth, histiocyte morphologic and phytohormone levels of pumpkin seedlings under different doses of End-Of-Day Far-Red light (EOD-FR) treatment, so as to provide a theoretical basis for the application of far-red in agricultural industry. 【Method】 Taken the pumpkin (cv. Japanese cedar) as experimental material, the growth state of hypocotyl’s histiocyte morphology and the contents of auxin (IAA), zeatin (ZT), gibberellin (GA₃) and brassinolide (BR) were measured under 0 (CK), 2 (T1) , 4 (T2) , 6 (T3) , 8 (T4) , 10 (T5) and 12 (T6) mmol·m^-2·d^-1dose far-red light treatments, respectively. 【Result】 The hypocotyl length and plant height of pumpkin seedlings were significantly increased by EOD-FR treatment, while there was no significant effect on the diameter, dry and fresh weight of pumpkin stem. Compared with the control group, the lengths of hypocotyl’s parenchyma cell of each treatment were significantly increased by 34.6%, 20.7%, 31.3%, 25.6%, 32.8% and 20.9%, respectively; the collenchyma's thickness were significant increased by 19.6%, 22.4%, 21.2%, 23.9%, 19.6% and 28%, respectively. After EOD-FR treatment, the contents of IAA in roots of pumpkin seedlings significantly increased, and the contents of IAA, GA₃ and ZT in hypocotyls, IAA, GA₃ and BR in cotyledons, IAA and BR in euphylla were also increased. 【Conclusion】Through increasing the hormone levels under EOD-FR treatment, the histiocyte morphology could be changed, and the hypocotyl elongation could be increased.
Keywords：far-red light;pumpkin seedlings;hypocotyl;cell morphology;phytohormone;regulative of far-red light


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本文引用格式
刘齐, 梅延豪, 李琦, 马宏秀, 武永军, 杨振超. 暗期短暂远红光处理对南瓜幼苗生长、细胞形态和激素含量的影响[J]. 中国农业科学, 2020, 53(20): 4248-4258 doi:10.3864/j.issn.0578-1752.2020.20.013
LIU Qi, MEI YanHao, LI Qi, MA HongXiu, WU YongJun, YANG ZhenChao. Effects of End of Day Far-Red Light on Growth, Histiocyte Morphology and Phytohormones Content of Pumpkin Seedlings[J]. Scientia Acricultura Sinica, 2020, 53(20): 4248-4258 doi:10.3864/j.issn.0578-1752.2020.20.013

0 引言

【研究意义】光照不仅可以作为植物生长的能量来源,对于植物形态建成也具有重要影响。外界光环境变化会极大地影响植物的生长形态,特别是在植物生长的早期阶段^[1]。随着设施农业的发展,人工补光成为设施栽培生产的一项关键技术。设施内光环境较外界相比,存在光强较弱与光谱较窄等问题,均不利于作物早期生长。因此,研究设施生产中远红光的合理应用及其影响植物生长的机制,对设施栽培生产具有重要意义。【前人研究进展】近年来,波长范围在700—800 nm的远红光开始受到研究人员的关注。已有研究发现设施内适当添加远红光照射,有助于调节光形态发生,在一定程度上促进叶片展开和茎伸长,有利于提高设施栽培产量,缩短作物生产时间,且不会导致植株茎叶过度生长^[2]。JI等^[3]发现,施加远红光后,可以提高番茄果实干重,但会降低叶片对于灰霉病的抵抗力;GOMMERS等^[4]通过对天竺葵的试验发现,添加一定强度的远红光照射后,会显著提高叶柄内IAA和GA₁的含量。有关研究表明,在一天暗期开始前,单独对植物进行短时间远红光处理（End-Of-Day Far-Red）,会导致植物出现与接受日间远红光处理（Day Far-Red）相类似的反应^[5]。浩二島^[6]和圭弘竹村 ^[7]分别在暗期前短时外施远红光处理菊花和桔梗,发现其茎均得到了显著伸长。STEWART等^[8]通过对燕麦的研究发现,暗期前短时外施远红光照射提高了幼苗鲜重与芽高,但对植株干重无显著影响。除植株形态外,暗期前外施远红光对植物组织细胞形态和多种激素含量也具有显著影响,如OLSEN等^[9]通过对山杨的研究发现,经过暗前远红光处理后,植株节间细胞数目和长度显著增加;曹凯等^[10]研究发现,暗期前远红光处理后,番茄叶片内IAA和GA₃的含量显著上升。【本研究切入点】尽管众多研究表明,暗期前短时外施远红光对植物生长发育造成显著影响,但有关其对植物不同组织、细胞形态与激素含量影响程度的研究却鲜有报道,且少有植株生长形态、组织细胞形态和激素水平三者之间变化关联的探究。【拟解决的关键问题】本试验以南瓜为研究对象,于每日暗期前单独照射不同剂量远红光,探究南瓜幼苗生长形态、组织与细胞形态以及生长素（IAA）、赤霉素（GA₃）、玉米素（ZT）和油菜素内酯（BR）4 种内源激素含量的变化,为完善和发展远红光调控植物生长理论提供依据。

1 材料与方法

试验于2019年在西北农林科技大学园艺学院进行。

1.1 试验材料

本试验以南瓜品种‘日本雪松’为材料,采用蒙大育苗基质育苗。试验处理所用LED灯板和控制器由西安因变科技有限公司提供。

1.2 试验设计

将南瓜种子置于室外晾晒8 h,使用55℃热水浸种10 min并不断搅拌,待水温下降至30℃以下,浸泡6 h捞出。使用无菌水冲洗种子表面并轻轻揉搓。30℃恒温培养箱催芽,种子萌发后,选择出芽长度一致的种子播入50孔穴盘内,覆盖基质并充分灌水,直至穴盘底部排水孔出现水滴。于日光温室内进行育苗。待幼苗出土、下胚轴直立,两片子叶完全展开时,选择长势均匀健壮,下胚轴长度一致的幼苗,作为待处理植株。试验共分为7个小组,每组20株。根据外施远红光剂量不同,共分为6个处理（表1）。于每天19:30进行远红光处理。试验所用远红光波长峰值在730 nm,光照强度为100 μmol·m^-2·s^-1,通过控制不同处理组处理时长进而达到外施不同远红光剂量的目的,连续处理6 d。夜间温度控制在24—27℃,湿度控制在60%—65%。于第二日7:30移至室外接受光照。试验期间外界环境稳定,无大风降雨等天气发生。

Table 1
表1
表1试验处理所用远红光处理时间、强度及剂量
Table 1Far-red light intensity, duration and dose

处理 Treament	照射持续时间 Duration (s)	远红光通量 FR photo flux (μmol·m-2·s-1)	远红光剂量 FR dose (mmol·m-2·d-1)
CK	0	0	0
T1	20	100	2
T2	40	100	4
T3	60	100	6
T4	80	100	8
T5	100	100	10
T6	120	100	12

远红光剂量数值等于照射持续时间×远红光通量
Dose was the product of far-red photon flux and duration of the treatment

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不同处理所用远红光强度、时间与剂量如表1所示:

1.3 测定项目与方法

1.3.1 下胚轴长度测定 于处理前1 d至处理第6天,每天17:00对南瓜幼苗下胚轴长度进行测量,具体方法为使用钢尺测量每株幼苗生长点到基质的距离。

1.3.2 生长指标的测定 处理后的第6天,每组随机取6株植株,测量株高、茎粗,使用感量为0.001 g的电子天平测定植株地上部和地下部干重和鲜重,并计算壮苗指数（壮苗指数=茎粗/株高×全株干重）。

1.3.3 细胞形态测定 处理6 d后在各小组中选取3株长势均匀健壮的植株,取其下胚轴中间部位制作石蜡切片。石蜡切片采用番红-固绿染色。使用正置荧光显微镜进行细胞观察和拍照,观察和测量细胞所采用的软件为CellSens Standard。

1.3.4 激素测定 处理3 d后,各小组选择7株幼苗,分别取其根部、下胚轴、子叶与真叶0.5 g,液氮速冻保存样品。使用酶联免疫法（Elisa）测定IAA、ZT、GA₃和BR 4种植物激素含量。具体方法参照文献[11,12]并相应改进,使用酶标仪为Thermo Multiskan MK3型。

1.4 数据分析

采用Excel对数据进行处理,数据的方差分析与显著性测试采用SPSS 19.0软件进行,采用单因素方差分析（ANOVA）进行数据比较,利用Duncan’s新复极差法检验处理间差异的显著性水平,并分别在P<0.01和P<0.05水平上进行检验。使用Origin 2017绘图。

2 结果

2.1 不同剂量的远红光对于南瓜幼苗下胚轴长度的影响

由图1可得,通过暗前远红光处理后,不同处理间南瓜幼苗下胚轴长度与对照组相比均显著伸长,且在处理第1天就达到了极显著水平（P<0.01）。处理第6天,各处理组植株下胚轴长度均极显著高于对照,其中下胚轴长度以T5最高,T1最低,但不同处理组间下胚轴长度均无显著差异（P>0.05）。

图1

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图1不同剂量的远红光对南瓜幼苗下胚轴长度的影响

Fig. 1Effects of different end-of-day FR doses on hypocotyl length of pumpkin seedlings

2.2 不同剂量的远红光处理对于南瓜幼苗其他生长指标和生物量的影响

由表2可知,与对照相比,各处理组南瓜幼苗株高均有一定程度的增加;而茎粗,地上、地下部干鲜重以及壮苗指数无显著变化（P>0.05）。这说明,当外施远红光的剂量在2—12 μmol·m^-2·d^-1时,对于南瓜幼苗茎粗以及生物量等指标无显著影响,而株高增加可能与下胚轴的伸长有关。

Table 2
表2
表2不同剂量的远红光处理对南瓜幼苗其他生长指标和生物量的影响
Table 2Effects of different doses of end-of-day FR on the other growth indicators and biomass of pumpkin seedlings

处理 Treatment	株高 Plant height (cm)	茎粗 Stem diameter (mm)	地上鲜重 Above ground fresh weight (g)	地下鲜重 Root fresh weight (g)	地上干重 Above ground part dry weight (g)	地下干重 Root dry weight (g)	壮苗指数 Index of vigorous seedings
CK	9.668±0.488bA	3.277±0.077aA	2.460±0.107aA	0.323±0.015aA	0.177±0.008aA	0.023±0.003aA	0.069±0.005aA
T1	10.998±0.480abA	3.303±0.100aA	2.970±0.155aA	0.380±0.034aA	0.191±0.010aA	0.023±0.002aA	0.065±0.006aA
T2	10.602±0.521abA	3.410±0.140aA	2.901±0.266aA	0.423±0.043aA	0.172±0.008aA	0.025±0.002aA	0.065±0.006aA
T3	10.620±0.471abA	3.133±0.110aA	2.836±0.092aA	0.351±0.037aA	0.177±0.007aA	0.020±0.001aA	0.058±0.003aA
T4	11.072±0.397abA	3.100±0.140aA	2.700±0.140aA	0.318±0.032aA	0.182±0.009aA	0.021±0.001aA	0.057±0.004aA
T5	11.383±0.235aA	3.457±0.118aA	2.887±0.144aA	0.321±0.017aA	0.174±0.008aA	0.021±0.001aA	0.059±0.004aA
T6	10.615±0.633abA	3.187±0.073aA	2.749±0.201aA	0.404±0.044aA	0.182±0.016aA	0.021±0.002aA	0.061±0.005aA

不同小写字母表示差异显著（P<0.05）,大写字母表示差异极显著（P<0.01）。下同
Different small letters and capital letters in the same column meant significant difference at 0.05 and 0.01 level among treatments, respectively. The same as below

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2.3 不同剂量的远红光处理对南瓜幼苗细胞形态的影响

2.3.1 对下胚轴纵切面细胞形态的影响 暗期前不同剂量远红光处理后,南瓜下胚轴薄壁细胞轴向长度显著增加,与对照组相比,分别增加了34.6%、20.7%、31.3%、25.6%、32.8%和20.9%（P<0.01）。与对照组相比,T3、T4与T6处理的薄壁细胞径向长度分别增加了14.3%、15.8%和11.1%（P<0.05）（图2）。

图2

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图2不同剂量的远红光处理对南瓜幼苗下胚轴薄壁细胞的影响

不同小写字母表示处理间差异达5%显著水平;不同大写字母表示处理间差异达1%显著水平。下同
Fig. 2Effects of different dose of end-of-day FR on the parenchyma cells of hypocotyl in pumpkin seedlings

Different lowercase letters after the same data column indicate a significant difference at 5% level between different treatments; capital letters indicate a significant difference at a 1% level between different treatments. The same as below


由表3可知,不同处理组筛管分子细胞轴向长度与对照组相比有所增加,其中T3、T4与T6达到了显著水平（P<0.05）。各处理间筛管分子细胞的径向长度无显著差异（P>0.05）。各处理组表皮细胞轴向长度与对照组相比,仅T3、T4与T6显著增加（P<0.05）,各组表皮细胞的径向长度无显著差异（P>0.05）。因此,暗期前短时远红光处理会导致南瓜下胚轴薄壁细胞轴向长度显著增加,对筛管分子细胞和表皮细胞轴向长度也具有一定的促进作用,但对筛管分子细胞、表皮细胞的径向长度无显著影响。

Table 3
表3
表3不同剂量的远红光处理对南瓜下胚轴纵切面筛管分子细胞和表皮细胞的影响
Table 3Effects of different doses of end-of-day FR on the Phloem cells and epidermal cells in vertical section of hypocotyl of pumpkin

处理 Treatment	筛管分子细胞轴向长度 Axial length (μm)	筛管分子细胞径向长度 Radial length (μm)	表皮细胞轴向长度 Axial length (μm)	表皮细胞径向长度 Radial length (μm)
CK	67.025±1.355bA	36.118±0.766aA	89.465±2.368cD	21.988±0.368aA
T1	69.620±1.632abA	37.226±0.918aA	93.426±2.605cCD	21.737±0.468aAB
T2	69.114±1.779abA	35.566±0.7191aA	96.210±3.026bcBCD	20.234±0.358bBC
T3	74.384±2.035aA	35.954±0.991aA	110.782±3.866aA	22.564±0.433aA
T4	74.309±2.105aA	37.464±0.724aA	91.352±1.875cD	22.666±0.440aA
T5	68.732±1.956abA	34.663±0.869aA	106.237±3.280aAB	22.148±0.444aA
T6	73.032±2.118aA	37.032±1.161aA	104.202±3.511abAB	19.656±0.481bC

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2.3.2 对下胚轴纵横切面组织与细胞的影响

2.3.2.1 对下胚轴厚角组织的影响 由图3可知,通过暗期前远红光处理后,南瓜下胚轴厚角组织厚度显著增加,各处理分别比对照组高19.6%,22.4%,21.2%,23.9%,19.6%和28%（P<0.01）。由图4可以看出,与对照组相比,各处理厚角组织细胞面积得到了一定程度的扩张。

图3

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图3不同剂量的远红光对南瓜下胚轴厚角组织厚度的影响

Fig. 3Effects of the different doses of end-of-day far-red light on the thickness of the collenchyma of pumpkin

图4

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图4不同剂量的远红光处理对南瓜下胚轴厚角组织形态的影响

Fig. 4Effects of the different doses of end-of-day far-red light on the collenchyma of pumpkin



2.3.2.2 对下胚轴皮层组织的影响 远红光处理后,南瓜下胚轴皮层组织厚度得到了提高,与对照组相比,分别提高了28.6%、6.8%、27.5%、5.1%、9.5%和31.4%,其中T1、T3和T6达到了极显著水平（P<0.01）（图5）。由此可见,暗期前外施远红光对南瓜幼苗下胚轴皮层增厚具有促进作用。

图5

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图5不同剂量的远红光对于南瓜下胚轴厚角组织厚度的影响

Fig. 5Effect of the different doses of end-of-day far-red light on the thickness of the cortex of pumpkin



2.3.2.3 对下胚轴导管细胞和维管束的影响 由表4可得,暗期前短时外施远红光对南瓜幼苗下胚轴导管细胞面积和维管束面积无显著影响（P>0.05）。

Table 4
表4
表4不同剂量的远红光处理对南瓜下胚轴导管细胞面积和维管束面积的影响
Table 4Effect of the different doses of end-of-day far-red light on the size of duct cells and the size of vascular of pumpkin

处理 Treatment	导管细胞面积 The size of duct cells (×102 μm2)	维管束面积 The size of vascular (×103 μm2)
CK	11.153±0.804aA	92.559±7.113abAB
T1	10.898±0.654aA	110.71±8.555aA
T2	11.323±0.650aA	97.097±4.855abAB
T3	12.135±0.674aA	96.939±7.441abAB
T4	10.997±0.501aA	87.595±5.354bB
T5	12.468±0.754aA	83.292±4.726bAB
T6	11.972±0.687aA	88.102±6.51bAB

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2.4 不同剂量的远红光处理对于南瓜幼苗内源激素水平的影响

2.4.1 对南瓜幼苗IAA水平的影响 暗期前外施远红光后,各小组IAA含量发生显著变化。根部IAA含量以T6最高,与对照相比,各处理分别增加34.3%、23.7%、4.6%、18.6%、32.6%和39.8%（P<0.05）,其中T1、T2、T5和T6都达到了极显著水平（P<0.01）。暗期前远红光处理后,T2、T4、T5、T6下胚轴内IAA含量均高于对照,其中T6处理比对照高16.8%,差异达显著（P<0.05）。子叶中IAA含量最高的处理为T6,6个处理分别比对照高33.3%、25.8%、21.4%、32.5%、32.1%和50.0%（P<0.05）,其中T1、T2、T4、T5和T6达到极显著水平（P<0.01）。真叶中IAA含量最高的处理为T1,各处理分别比对照高30.7%、11.1%、29.0%、11.7%、27.2%和10.3%（P<0.05）,其中T1、T3和T5达到极显著水平（P<0.01）（表5）。经过不同剂量的远红光处理后,南瓜幼苗IAA含量呈现上升趋势。对于南瓜幼苗不同部位而言,IAA的含量也存在差异,叶片中IAA含量要明显高于根和下胚轴。

Table 5
表5
表5不同剂量的远红光处理对于南瓜幼苗IAA水平的影响
Table 5Effect of the different doses of end-of-day far-red light on content of IAA in pumpkin

处理 Treatment	根中IAA质量分数 The content of IAA in root (ng?g-1 FW)	下胚轴中IAA质量分数 The content of IAA in hypocotyl (ng?g-1 FW)	子叶中IAA质量分数 The content of IAA in cotyledon (ng?g-1 FW)	真叶中IAA质量分数 The content of IAA in euphylla (ng?g-1 FW)
CK	23.163±0.757dC	29.614±1.21bcdA	39.854±1.357cC	39.139±1.180bD
T1	31.118±1.283abA	29.359±1.493cdA	53.109±0.891bAB	51.137±2.246aA
T2	28.664±1.373abAB	31.993±1.289abcdA	50.130±1.698bAB	43.475±0.892bBCD
T3	24.235±0.994cdBC	29.004±0.835cA	48.372±0.380bBC	50.501±1.317aAB
T4	27.471±1.762bcABC	34.399±2.031abA	52.805±2.420bAB	43.726±2.277bBCD
T5	30.719±0.733abA	33.942±2.036abcA	52.649±0.837bAB	49.795±1.312aABC
T6	32.385±0.86aA	34.598±0.894aA	59.778±4.592aA	43.156±1.303bCD

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2.4.2 对南瓜幼苗ZT水平的影响 由表6可知,通过暗期前短时外施远红光处理,南瓜幼苗ZT含量差异主要体现在下胚轴上。下胚轴ZT含量以T5最高,各处理比对照分别增加24.2%、21.8%、40.9%、37.5%、40.9%和17.9%,其中T1、T2、T3、T4和T5达到极显著差异（P<0.01）。在南瓜幼苗的不同部位,子叶中ZT含量明显高于其他位置,真叶次之,根与下胚轴中ZT含量最少。

Table 6
表6
表6不同剂量的远红光处理对南瓜幼苗ZT水平的影响
Table 6Effects of the different doses of end-of-day far-red light on content of ZT in pumpkin

处理 Treatment	根中ZT质量分数 The content of ZT in root (ng?g-1 FW)	下胚轴中ZT质量分数 The content of ZT in hypocotyl (ng?g-1 FW)	子叶中ZT质量分数 The content of ZT in cotyledon (ng?g-1 FW)	真叶中ZT质量分数 The content of ZT in euphylla (ng?g-1 FW)
CK	4.618±0.147bcB	3.750±147dC	11.217±0.356bB	7.703±0.302bB
T1	5.543±0.165aA	4.659±0.262bcAB	11.521±0.493bcAB	7.741±0.407bB
T2	4.738±0.211bcB	4.566±0.149cAB	12.360±0.332abAB	7.077±0.241bcB
T3	4.290±0.111cB	5.282±0.177aA	12.912±0.363aA	7.305±0.332bcB
T4	4.696±0.143bcB	5.155±0.250abAB	12.185±0.389abAB	9.135±0.362aA
T5	4.310±0.223cB	5.285±0.116aA	11.226±0.286bcB	6.599±0.299cB
T6	5.025±0.141bAB	4.421±0.114cBC	10.926±0.201cB	6.521±0.272cB

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2.4.3 对南瓜幼苗GA₃水平的影响 南瓜幼苗GA₃含量在远红光处理后表现出差异（表7）,其中下胚轴和子叶GA₃含量变化较大,下胚轴中GA₃含量最高的处理组为T5,各处理分别比对照高9.9%、7.4%、19.2%、2.3%、27.4%和16.7%,其中T3、T5和T6达到显著水平（P<0.05）。子叶中GA₃含量以T3最高,各处理分别比对照增加6.3%、6.6%、24.0%、4.2%、8.1%和14.5%,其中T3和T6与对照的差异达到显著水平（P<0.05）。GA₃在植物体内的含量以子叶和新叶内居多,根部次之,下胚轴含量较低。

Table 7
表7
表7不同剂量的远红光处理对南瓜幼苗GA₃水平的影响
Table 7Effects of the different doses of end-of-day far-red light on content of GA₃ in pumpkin

处理 Treatment	根中GA3质量分数 The content of GA3 in root (ng?g-1FW)	下胚轴中GA3质量分数 The content of GA3 in hypocotyl (ng?g-1FW)	子叶中GA3质量分数 The content of GA3 in cotyledon (ng?g-1FW)	真叶中GA3质量分数 The content of GA3 in euphylla (ng?g-1FW)
CK	5.201±0.123bBC	4.461±0.112cB	6.742±0.309cB	6.966±0.135cdBC
T1	5.633±0.015bAB	4.902±0.314bcB	7.167±0.164bcB	8.161±0.156aA
T2	4.769±0.205cC	4.789±0.175bcB	7.187±0.140bcB	7.706±0.402abABC
T3	5.596±0.103bAB	5.316±0.136abAB	8.362±0.425aA	6.580±0.276dC
T4	5.410±0.204bB	4.562±0.119cB	7.027±0.084bcB	6.562±0.130dC
T5	5.418±0.160bB	5.683±0.218aA	7.290±0.059bcAB	7.090±0.076bcdBC
T6	6.125±0.050aA	5.205±0.160abAB	7.722±0.375abAB	7.439±0.182bcABC

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2.4.4 对南瓜幼苗BR水平的影响 暗期前短时远红光处理后,南瓜幼苗叶片内BR含量发生显著变化。子叶内BR含量以T3最高,T1、T2、T3、T5的BR含量分别比对照提高了14.7%、10.0%、24.7%和22.7%,其中,T1、T3和T5子叶内BR含量与对照差异达到显著水平（P<0.05）。与对照相比,各处理真叶中BR含量分别提高了17%、25.3%、32.6%、39.0%、39.5%和16.0%（P<0.05）（表8）。不同处理的根与下胚轴内BR含量变化无明显规律。此外,同剂量处理下,真叶中BR含量均明显高于其他组织。

Table 8
表8
表8不同剂量的远红光处理对南瓜幼苗BR水平的影响
Table 8Effect of the different doses of end-of-day far-red light on content of BR in pumpkin

处理 Treatment	根中BR质量分数 The content of BR in root (ng?g-1 FW)	下胚轴中BR质量分数 The content of BR in hypocotyl (ng?g-1 FW)	子叶中BR质量分数 The content of BR in cotyledon (ng?g-1 FW)	真叶中BR质量分数 The content of BR in euphylla (ng?g-1 FW)
CK	5.528±0.343abAB	5.901±0.222aA	5.108±0.144bB	5.432±0.119cC
T1	4.466±0.198dB	4.022±0.217cB	5.860±0.172aAB	6.357±0.309bBC
T2	5.185±0.097abcdAB	6.236±0.171aA	5.619±0.217bcAB	6.805±0.223abAB
T3	4.944±0.114bcdAB	5.665±0.199aA	6.370±0.168aA	7.205±0.0316aAB
T4	5.906±0.381aA	5.852±0.256aA	5.060±0.158bB	7.550±0.310aA
T5	4.648±0.302cdB	4.720±0.115bB	6.270±0.348aA	7.576±0.445aA
T6	5.410±0.215abcAB	6.245±0.24aA	5.054±0.338bB	6.303±0.183bBC

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3 讨论

相关研究表明,远红光在光合作用过程中效率较低。若光谱内添加较多远红光时,会导致植株的光合效率下降^[13]。而VIR?IL?等^[14]研究表明,在日间光谱中添加微量（2%）远红光后,将显著影响乌塌菜多种内含物质含量。说明远红光对植物的作用更多的是作为信号传导而不是直接参与光合作用。远红光作为调控植物形态建成的重要信号,由植物体内特定的光受体接收,即两种不同的光敏色素（Pr与Pfr）,其中活跃的远红光吸收型pfr吸收远红光会转换为不活跃的红光吸收型pr^[15]。因此,环境中R:FR的比值对植物体内两种光敏色素的相对含量具有重要影响,进而导致植物体内产生一系列生理反应^[16]。而暗期开始前对植株进行远红光照射,可以加速植物体内的Pfr转换为Pr,使植物夜间Pfr含量保持较低水平^[17],进而对植株形态产生显著影响。前人研究表明,暗期前短时远红光处理会显著影响植物的生长形态,导致番茄^[10,18]、西瓜^[19]、黄瓜^[20]茎的伸长,且对植株生物量等指标无显著影响。本研究结果与前人所得结论一致,不同处理组下胚轴伸长的同时,植株茎粗与干重等指标无显著变化。本试验所用远红光剂量范围为2—12 mmol·m^-2·d^-1,随着远红光剂量不断增加,下胚轴表现出先迅速伸长后逐渐变缓并趋于稳定的趋势,这与CHIA等^[18]研究结果一致。CHIA等^[18]研究还表明,当外施远红光剂量为1 mmol·m^-2·d^-1时,试验处理植株下胚轴长度与其他处理组间有一定差距;当远红光剂量达到2 mmol·m^-2·d^-1以上时,植株下胚轴长度不再出现差异。本试验结果与其相似,出现差异部分可能与试验材料选择有关。本试验中外施远红光剂量为2 mmol·m^-2·d^-1时,下胚轴长度小于其他处理组但未达到显著水平;当远红光剂量增加至4 mmol·m^-2·d^-1以上时,下胚轴伸长与远红光剂量之间规律性不明显,此时高剂量远红光处理可能无法有效促进下胚轴进一步伸长,还会造成实践中的能源浪费。因此,对于试验材料而言,使用暗前远红光调控下胚轴伸长剂量范围以2—4 mmol·m^-2·d^-1最适宜,既可调控植株下胚轴快速伸长,又可减少调控过程中无意义的能源消耗。除下胚轴长度显著变化外,本试验还得出下胚轴不同组织与细胞形态变化结果,这可能是导致植株形态发生变化的直接原因。

外界光环境的改变对于植物组织与细胞的形态结构同样具有重大影响^[21]。前人研究结果表明,低R:FR会导致细胞发生变化,进而影响植株形态^[22]。MOUTINHO-PEREIRA等^[23]通过对葡萄的研究发现,随着外界光环境中R:FR比值减小,其叶片薄壁组织厚度得到增加。本试验中,通过观察植株下胚轴纵切面发现,薄壁细胞轴向长度均显著增加。通过观察下胚轴横切面发现,厚角组织与皮层组织得到不同程度增厚,厚角组织对于正在旺盛生长的植物具有重要的作用与意义^[24],若没有厚角组织的机械支持作用,植物在成长初期的高度将受到抑制^[25]。厚角组织增厚原因目前尚不明确,还需更加深入探究。皮层组织和厚角组织具有相似的功能,前期具有一定的支持能力,同时还具有一定的营养储存功能。皮层组织的增厚与薄壁细胞扩张生长有密切联系。薄壁细胞长度增加可能是下胚轴伸长的重要因素,厚角组织与皮层组织厚度的增加,增强了下胚轴的支持能力,这在设施蔬菜砧木培育上具有重要意义^[18]。下胚轴组织与细胞的变化,可能是导致植株形态改变的直接原因;而组织与细胞的变化,则依赖于多种植物激素协调作用。

外界光环境改变会影响植物自身信号传导和激素水平变化^[26],进而影响植物生长发育。前人研究表明,在暗期前短时外施一定强度的远红光,能够显著提高植物不同部位IAA和GA的含量^[10,27]。本研究同样得出相似结论,通过暗期前短时外施远红光处理,南瓜幼苗不同部位IAA、GA₃、ZT与BR含量均发生一定程度变化。其中根、下胚轴、子叶与真叶内IAA含量均有一定程度的提高,说明IAA对于远红光介导的植株伸长具有重要作用^[28]。皮层组织增厚可能与生长素促进薄壁细胞分裂与生长有关^[29,30]。南瓜幼苗下胚轴和子叶内GA₃含量显著提升,GA₃可以促进细胞伸长,增加细胞壁延展性^[31],对下胚轴细胞伸长具有积极作用。ZT对于调控细胞分裂与分化具有重要意义,研究发现,在组织培养中,外施ZT可以显著促进细胞增殖^[32]。本试验通过暗前短时远红光处理后,植株下胚轴内ZT含量显著增加。这说明南瓜下胚轴伸长可能是由下胚轴细胞扩张与增殖共同决定。BR与IAA和GA₃具有类似的生理作用,可以与多种激素相互协调,对细胞分裂与扩张以及下胚轴的伸长具有重要的生理意义^[33,34]。经处理后叶片内BR含量显著提高,这有利于光合产物的运输,协调营养物质分配,进而促进植株下胚轴生长^[35]。通过暗期前远红光处理,4种植物激素间复杂而交叉的调控过程,是导致植株下胚轴组织细胞形态变化的重要原因,并最终导致南瓜下胚轴发生显著伸长。该操作方法简便易行,对设施内许多砧木幼苗的生产具有潜在价值。

4 结论

暗期前短时远红光处理导致南瓜幼苗下胚轴长度显著增加。本试验条件下,远红光剂量以2—4 mmol·m^-2·d^-1对下胚轴伸长最有利。暗期前短时外施远红光可以显著影响南瓜幼苗不同内源激素水平,特别是植株内IAA含量,进而促进幼苗下胚轴薄壁细胞伸长生长,最终导致植株下胚轴显著伸长,对下胚轴初生机械组织也具有一定程度的增强。

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[1] SASSI M, RUBERTI I, VERNOUX T, XU J. Shedding light on auxin movement: Light-regulation of polar auxin transport in the photocontrol of plant development
Plant Signaling & Behavior, 2013,8(3):e23355.
DOI:10.4161/psb.23355URLPMID:23333970 [本文引用: 1]
By being sessile, plants have evolved a remarkable capacity to perceive and respond to changes in environmental conditions throughout their life cycle. Light represents probably the most important environmental factor that impinge on plant development because, other than supplying the energy source for photosynthesis, it also provides seasonal and positional information that are essential for the plant survival and fitness. Changes in the light environment can dramatically alter plant morphogenesis, especially during the early phases of plant life, and a compelling amount of evidence indicates that light-mediated changes in auxin homeostasis are central in these processes. Auxin exerts its morphogenetic action through instructive hormone gradients that drive developmental programs of plants. Such gradients are formed and maintained via an accurate control on directional auxin transport. This review summarizes the recent advances in understanding the influence of the light environment on polar auxin transport.

[2] PARK Y, RUNKLE E S. Investigating the merit of including far-red radiation in the production of ornamental seedlings grown under sole-source lighting
Acta Horticulturae, 2016,1134(1134):259-266.
[本文引用: 1]

[3] JI Y R, OUZOUNIS T, COURBIER S, KAISER E, NGUYEN P T, SCHOUTEN H J, VISSER R G F, PIERIK R, MARCELIS L F M, HEUVELINK E. Far-red radiation increases dry mass partitioning to fruits but reduces Botrytis cinerea resistance in tomato
Environmental and Experimental Botany, 2019,168:103889.
DOI:10.1016/j.envexpbot.2019.103889URL [本文引用: 1]

[4] GOMMERS C M M, BUTI S, TARKOWSKá D, PěN?íK A, BANDA J P, ARRICASTRES V, PIERIK R. Organ-specific phytohormone synthesis in two Geranium species with antithetical responses to far-red light enrichment
Plant Direct, 2018,2(8):e66.
[本文引用: 1]

[5] KALAITZOGLOU P, VAN IEPEREN W, HARBINSON J, VAN DER MEER M, MARTINAKOS S, WEERHEIM K, NICOLE C C S, MARCELIS L F M. Effects of continuous or end-of-day far-red light on tomato plant growth, morphology, light absorption, and fruit production
Frontiers in Plant Science, 2019,10:322.
DOI:10.3389/fpls.2019.00322URLPMID:30984211 [本文引用: 1]
Shading by sunlit leaves causes a low red (R) to far-red (FR) ratio that results in a low phytochrome stationary state (PSS). A low PSS induces an array of shade avoidance responses that influence plant architecture and development. It has often been suggested that this architectural response is advantageous for plant growth due to its positive effect on light interception. In contrast to sunlight, artificial light sources such as LEDs often lack FR, resulting in a PSS value higher than solar light ( approximately 0.70). The aim of this study was to investigate how PSS values higher than solar radiation influence the growth and development of tomato plants. Additionally, we investigated whether a short period of FR at the end of the day (EOD-FR) could counteract any potentially negative effects caused by a lack of FR during the day. Tomato plants were grown at four PSS levels (0.70, 0.73, 0.80, and 0.88), or with a 15-min end-of-day far-red (EOD-FR) application (PSS 0.10). Photosynthetic Active Radiation (PAR; 150 mumol m(-2) s(-1)) was supplied using red and blue (95/5%) LEDs. In an additional experiment, the same treatments were applied to plants receiving supplementary low-intensity solar light. Increasing PSS above solar PSS resulted in increased plant height. Leaf area and plant dry mass were lower in the treatments completely lacking FR than treatments with FR. EOD-FR-treated plants responded almost similarly to plants grown without FR, except for plant height, which was increased. Simulations with a 3D-model for light absorption revealed that the increase in dry mass was mainly related to an increase in light absorption due to a higher total leaf area. Increased petiole angle and internode length had a negative influence on total light absorption. Additionally, the treatments without FR and the EOD-FR showed strongly reduced fruit production due to reduced fruit growth associated with reduced source strength and delayed flowering. We conclude that growing tomato plants under artificial light without FR during the light period causes a range of inverse shade avoidance responses, which result in reduced plant source strength and reduced fruit production, which cannot be compensated by a simple EOD-FR treatment.

[6] 浩二島. 明期終了時における遠赤色光照射の光強度および照射時間がスプレーギクの茎伸長に及ぼす影響
園芸学研究. 2011,10(3):401-406.
[本文引用: 1]

KOHJI S. Effect of the irradiance and duration with far-red light at the end of day (eod-fr) on stem elongation of spray type chrysanthemum
Horticultural Research (Japan), 2011,10(3):401-406. (in Japanese)
[本文引用: 1]

[7] 圭弘竹村. 明期終了時の遠赤色光照射処理および昇温処理がトルコギキョウの生育に及ぼす影響
園芸学研究, 2014,13(3):255-260.
[本文引用: 1]

YOSHIHIRO T. Effect of far-red light and heating treatment at end of day on growth of eustoma grandiflorum (Raf.) Shinn
.Horticultural Research (Japan), 2014,13(3):255-260. (in Japanese)
[本文引用: 1]

[8] STEWART S J, PRATT L H, CORDONNIER-PRATT I M. Phytochrome levels in light-grown avena change in response to end-of-day irradiations
Plant Physiology, 1992,99(4):1708-1710.
URLPMID:16669098 [本文引用: 1]

[9] OLSEN J E, JUNTTILA O. Far red end-of-day treatment restores wild type‐like plant length in hybrid aspen overexpressing phytochrome A
Physiologia Plantarum, 2002,115(3):448-457.
DOI:10.1034/j.1399-3054.2002.1150315.xURLPMID:12081538 [本文引用: 1]
Shoot elongation in woody plants is modulated by a multitude of light signals, including irradiance, photoperiod and spectral composition, for which the phytochrome system is the probable photoreceptor. In hybrid aspen (Populus tremula x tremuloides) overexpression of the oat phytochrome A (PHYA) prevents growth cessation in response to short photoperiod, and plants exhibit dwarf growth that is related to reduced cell numbers and reduced gibberellin contents. End-of-day far-red treatment significantly enhances internode elongation in PHYA overexpressors as well as in the wild type, and this was found here to be caused by stimulation of cell division and cell extension. In PHYA overexpressors the effects were substantially larger than in the wild type, and resulted in complete restoration of wild type-like plant length as well as cell numbers, and gibberellin content was greatly increased. No clear effect of far-red end-of-day treatment on gibberellin levels could be detected in the wild type. It thus appears that the far-red end-of-day treatment might modify the responsiveness of the tissue to GA rather than the GA levels. The observed effects were completely reversed by a subsequent irradiation with red light. The present data show that dwarfism due to PHYA overexpression can be completely overcome by far red end-of-day treatment, and the observations indicate that effects of far red end-of-day treatments appear to be mediated by phytochrome(s) other than phytochrome A.

[10] 曹凯, 于捷, 叶林, 赵海亮, 邹志荣. 暗前适宜LED远红光光照强度促进设施番茄种苗生长发育
农业工程学报, 2016,32(8):171-176.
URL [本文引用: 3]
为了研究LED光源在设施番茄育苗生产上的精准化利用。该试验以金鹏1号番茄植株为试材，研究了进入黑暗前LED远红光处理对番茄植株形态、激素含量、光合速率和矿质元素含量的影响。结果表明，当番茄植株进入黑暗前进行10 min远红光处理，番茄植株的株高及茎的鲜质量发生了明显变化，番茄植株的株高和茎的鲜质量随着远红光光照强度的增加而增加，当远红光的光照强度增加到10 μmol/(m2·s)时番茄植株的株高和茎的鲜质量也达到了最大值。与对照相比，进入黑暗前进行时长10 min，光照强度为10 μmol/(m2·s)的远红光处理后番茄植株叶片中的生长素和赤霉素3的含量显著上升；叶绿素和净光合速率显著降低；番茄植株茎中N含量显著降低，叶中P含量显著降低，K含量显著升高，根系中的N、P、K含量都显著增加。因此，可以通过调控黑暗前远红光的光照强度来精确调控番茄植株的株高，控制番茄的生长。
CAO K, YU J, YE L, ZHAO H L, ZOU Z R. Optimal LED far-red light intensity in end-of-day promoting tomato growth and development in greenhouse
Transactions of the Chinese Society of Agricultural Engineering, 2016,32(8):171-176. (in Chinese)
URL [本文引用: 3]
为了研究LED光源在设施番茄育苗生产上的精准化利用。该试验以金鹏1号番茄植株为试材，研究了进入黑暗前LED远红光处理对番茄植株形态、激素含量、光合速率和矿质元素含量的影响。结果表明，当番茄植株进入黑暗前进行10 min远红光处理，番茄植株的株高及茎的鲜质量发生了明显变化，番茄植株的株高和茎的鲜质量随着远红光光照强度的增加而增加，当远红光的光照强度增加到10 μmol/(m2·s)时番茄植株的株高和茎的鲜质量也达到了最大值。与对照相比，进入黑暗前进行时长10 min，光照强度为10 μmol/(m2·s)的远红光处理后番茄植株叶片中的生长素和赤霉素3的含量显著上升；叶绿素和净光合速率显著降低；番茄植株茎中N含量显著降低，叶中P含量显著降低，K含量显著升高，根系中的N、P、K含量都显著增加。因此，可以通过调控黑暗前远红光的光照强度来精确调控番茄植株的株高，控制番茄的生长。

[11] QIN S S, CHEN X Y, JIANG C, LI M J, YUAN Y, YANG J, WU Q H. Pruning induced yield and quality variations and the correlated gene expression and phytohormone changes in Lonicera japonica
Industrial Crops and Products, 2019,132:386-395.
DOI:10.1016/j.indcrop.2019.02.048URL [本文引用: 1]

[12] PRADKO A G, LITVINOVSKAYA R P, SAUCHUK A L, DRACH S V, BARANOVSKY A V, ZHABINSKII V N, MIRANTSOVA T V, KHRIPACH V A. A new ELISA for quantification of brassinosteroids in plants
Steroids, 2015,97:78-86.
URLPMID:25201263 [本文引用: 1]

[13] CHEN X L, GUO W Z, XUE X Z, WANG L C, QIAO X J. Growth and quality responses of ‘Green Oak Leaf’ lettuce as affected by monochromic or mixed radiation provided by fluorescent lamp (FL) and light-emitting diode (LED)
Scientia Horticulturae, 2014,172:168-175.
DOI:10.1016/j.scienta.2014.04.009URL [本文引用: 1]
Seeds of 'Green Oak Leaf' lettuce were sown and hydroponically cultured for 50 days (with no transplanting) under different light spectra from the following six lights: fluorescent light plus red LED (FLR), fluorescent light plus blue LED (FLB), monochromic red (R) or blue (B) LED, mixed red and blue LED (RB), and fluorescent light (FL), with equivalent photoperiod (14 h), PPF (133 +/- 5 mu mol m(-2) s(-1)), and other cultivation conditions. At seedling stage, highest height-growth rate was obtained-under FLR and R, plantlets under FLR showed improved morphology that was large and compact while those under monochromic R appeared sparse and fragile. Seedling growth was promoted under FLR and FLB, while inhibited the most under monochromic B as compared to FL At harvest stage, fresh weight, dry weight and stem diameter were greatest under FLR followed by FLB and lowest under monochromatic B and RB. Chlorophyll and carotenoid contents were also significantly higher under FLR and FLB and lowest under R and FL. The soluble sugar and nitrate contents were significantly higher in plantlets cultured under FL than those under LED or mixture lights of FL and LED. When cultured under FLB, vitamin C content was significantly lower but no significant difference was observed among other treatments. In conclusion, FLR and FLB resulted in improved morphology, greater biomass and pigment contents of lettuce than monochromic R, B, FL or RB. FL mixed with R or B LED could be used as efficient light sources for hydroponic cultivation of 'Green Oak Leaf' lettuce. (C) 2014 Elsevier B.V.

[14] VIR?IL? A, BRAZAITYT? A, VA?TAKAIT?-KAIRIEN? V, JANKAUSKIEN? J, MILIAUSKIEN? J, SAMUOLIEN? G, NOVI?KOVAS A, DUCHOVSKIS P. Nitrate, nitrite, protein, amino acid contents, and photosynthetic and growth characteristics of tatsoi cultivated under various photon flux densities and spectral light compositions
Scientia Horticulturae, 2019,258:108781.
DOI:10.1016/j.scienta.2019.108781URL [本文引用: 1]

[15] 杨有新, 王峰, 蔡加星, 喻景权, 周艳虹. 光质和光敏色素在植物逆境响应中的作用研究进展
园艺学报, 2014,41(9):1861-1872.
URL [本文引用: 1]
光敏色素是植物感受外界光环境变化最重要的光受体之一，不仅参与调控植物生长发育，
还介导植物对各种生物和非生物胁迫的响应。已有研究表明，光敏色素缺失会导致植物对病原菌、害虫
等生物胁迫以及低温、高温、干旱、盐等非生物胁迫的抗性发生改变；改变光质（如调节红光远红光比
率）可提高植物对上述逆境胁迫的抗性，并且通过水杨酸、茉莉酸和脱落酸等激素信号途径诱导植物的
抗性。在系统综述近年来光敏色素在逆境响应中的作用以及防御机制研究进展的基础上，讨论了在园艺
植物生产中通过利用光质和对光敏色素信号途径相关基因进行遗传改良，提高作物抗性，促进作物增产
和改善作物品质的重要性。
YANG Y X, WANG F, CAI J X, YU J Q, ZHOU Y H. Recent advances in the role of light quality and phytochrome in plant defense resistance against environmental stresses
Acta Horticulturae Sinica, 2014,41(9):1861-1872. (in Chinese)
URL [本文引用: 1]
光敏色素是植物感受外界光环境变化最重要的光受体之一，不仅参与调控植物生长发育，
还介导植物对各种生物和非生物胁迫的响应。已有研究表明，光敏色素缺失会导致植物对病原菌、害虫
等生物胁迫以及低温、高温、干旱、盐等非生物胁迫的抗性发生改变；改变光质（如调节红光远红光比
率）可提高植物对上述逆境胁迫的抗性，并且通过水杨酸、茉莉酸和脱落酸等激素信号途径诱导植物的
抗性。在系统综述近年来光敏色素在逆境响应中的作用以及防御机制研究进展的基础上，讨论了在园艺
植物生产中通过利用光质和对光敏色素信号途径相关基因进行遗传改良，提高作物抗性，促进作物增产
和改善作物品质的重要性。

[16] HOLMES M, SMITH H. The function of phytochrome in the natural environment: I. Characterization of daylight for studies in photomorphogenesis and photoperiodism
Photochemistry and Photobiology, 2008,25(6):533-538.
DOI:10.1111/php.1977.25.issue-6URL [本文引用: 1]

[17] FRANKLIN K A. Shade avoidance
New Phytologist, 2008,179(4):930-944.
DOI:10.1111/j.1469-8137.2008.02507.xURLPMID:18537892 [本文引用: 1]
The threat to plant survival presented by light limitation has driven the evolution of highly plastic adaptive strategies to either tolerate or avoid shading by neighbouring vegetation. When subject to vegetational shading, plants are exposed to a variety of informational signals, which include altered light quality and a reduction in light quantity. The former includes a decrease in the ratio of red to far-red wavelengths (low R : FR) and is detected by the phytochrome family of plant photoreceptors. Monitoring of R : FR ratio can provide an early and unambiguous warning of the presence of competing vegetation, thereby evoking escape responses before plants are actually shaded. The molecular mechanisms underlying physiological responses to alterations in light quality have now started to emerge, with major roles suggested for the PIF (PHYTOCHROME INTERACTING FACTOR) and DELLA families of transcriptional regulators. Such studies suggest a complex interplay between endogenous and exogenous signals, mediated by multiple photoreceptors. The phenotypic similarities between physiological responses habitually referred to as 'the shade avoidance syndrome' and other abiotic stress responses suggest plants may integrate common signalling mechanisms to respond to multiple perturbations in their natural environment.

[18] CHIA P, KUBOTA C. End-of-day far-red light quality and dose requirements for tomato rootstock hypocotyl elongation
HortScience, 2010,45(10):1501-1506.
DOI:10.21273/HORTSCI.45.10.1501URL [本文引用: 4]

[19] GRAHAM H H A, DECOTEAU D R. Young watermelon plant growth responses to end-of-day red and far-red light are affected by direction of exposure and plant part exposed
Scientia Horticulturae, 1997,69(2):41-49.
DOI:10.1016/S0304-4238(96)00991-0URL [本文引用: 1]

[20] XIONG J Q, PATIL G G, MOE R. Effect of DIF and end-of-day light quality on stem elongation in Cucumis sativus
Scientia Horticulturae, 2002,94(4):219-229.
DOI:10.1016/S0304-4238(02)00002-XURL [本文引用: 1]

[21] HALIAPAS S, YUPSANIS T A, SYROS T D, KOFIDIS G, ECONOMOU A S. Petunia × hybrida during transition to flowering as affected by light intensity and quality treatments
Acta Physiologiae Plantarum, 2008,30(6):807-815.
DOI:10.1007/s11738-008-0185-zURL [本文引用: 1]
Petunia×hybrida was grown under high (H), medium (M) and low (L) light intensity [photoperiod; 16hd⁻¹, photosynthetic photon flux density (PPFD); 360, 120 and 40μmolm⁻²s⁻¹, respectively] as well as under end-of-day (EOD) red (R) and far-red (FR) light quality treatments [photoperiod; 14.5hd⁻¹, PPFD; 30μmolm⁻²s⁻¹ EOD; 15min, Control (C) light; without EOD light treatment]. Shoot growth, leaf anatomical and photosynthetic responses as well as the responses of peroxidase (POD) isoforms and their specific activities following transition to flowering (1–6weeks) were evaluated. Flower bud formation of Petunia×hybrida was achieved at the end of the 4th week for H light treatment and on the end of the 6th week for FR light treatment. No flower bud formation was noticed in the C and R light treatments. H and M light treatments induced lower chlorophyll (Chla, Chlb, Chla+b) concentrations in comparison to L light. On the other hand R and FR light chlorophyll content were similar to C light. Photosynthetic parameters [CO₂ assimilation rate (A), transpiration rate (E) and stomatal conductance (g _s) values] were higher in the H light treated plants in comparison to M and L light treated plants. A, E and g _s values of R and FR light were similar to C light plants. Leaf anatomy revealed that total leaf thickness, thickness of the contained tissues (epidermis, palisade and spongy parenchyma) and relative volume percentages of the leaf histological components were differently affected within the light intensity and the light quality treatments. POD specific activities increased from the 1st to the 6th week during transition to flowering. Native-PAGE analysis revealed the appearance of four anionic POD (A₁–A₄) isoforms in all light treatments. On the basis of the leaf anatomical, photosynthetic and plant morphological responses, the production of high quality Petunia×hybrida plants with optimal flowering times could be achieved through the control of both light intensity and light quality. The appearance of A₁ and A₂ anionic POD isoforms could be also used for successful scheduling under light treatments.

[22] SASIDHARAN R, CHINNAPPA C C, VOESENEK L A C J, PIERIK R. The regulation of cell wall extensibility during shade avoidance: a study using two contrasting ecotypes of Stellaria longipes
Plant Physiology, 2008,148(3):1557-1569.
DOI:10.1104/pp.108.125518URLPMID:18768908 [本文引用: 1]
Shade avoidance in plants involves rapid shoot elongation to grow toward the light. Cell wall-modifying mechanisms are vital regulatory points for control of these elongation responses. Two protein families involved in cell wall modification are expansins and xyloglucan endotransglucosylase/hydrolases. We used an alpine and a prairie ecotype of Stellaria longipes differing in their response to shade to study the regulation of cell wall extensibility in response to low red to far-red ratio (R/FR), an early neighbor detection signal, and dense canopy shade (green shade: low R/FR, blue, and total light intensity). Alpine plants were nonresponsive to low R/FR, while prairie plants elongated rapidly. These responses reflect adaptation to the dense vegetation of the prairie habitat, unlike the alpine plants, which almost never encounter shade. Under green shade, both ecotypes rapidly elongate, showing that alpine plants can react only to a deep shade treatment. Xyloglucan endotransglucosylase/hydrolase activity was strongly regulated by green shade and low blue light conditions but not by low R/FR. Expansin activity, expressed as acid-induced extension, correlated with growth responses to all light changes. Expansin genes cloned from the internodes of the two ecotypes showed differential regulation in response to the light manipulations. This regulation was ecotype and light signal specific and correlated with the growth responses. Our results imply that elongation responses to shade require the regulation of cell wall extensibility via the control of expansin gene expression. Ecotypic differences demonstrate how responses to environmental stimuli are differently regulated to survive a particular habitat.

[23] MOUTINHO-PEREIRA J M, BACELAR E A, GON?ALVES B, FERREIRA H F, COUTINHO J F, CORREIA C M. Effects of Open-Top Chambers on physiological and yield attributes of field grown grapevines
Acta Physiologiae Plantarum, 2010,32(2):395-403.
DOI:10.1007/s11738-009-0417-xURL [本文引用: 1]
Touriga Franca grapevines were grown in Open-Top Chamber (OTC) and in outside plot (Exterior) for 3years (2004–2006) to investigate the impact of these structures on climatic conditions and, consequently, on physiological and yield attributes. In general, CO₂ assimilation, stomatal conductance, carbohydrate concentration, maximum bulk modulus of elasticity, palisade parenchyma thickness, leaf mass per unit area and values of red/far-red ratio transmitted by leaves were lower, whereas intrinsic water use efficiency, SPAD-readings and osmotic potential at full turgor were higher in OTC leaves. However, OTC did not affect leaf water potential, maximum PSII photochemical efficiency, stomatal density and soluble proteins concentration. Also, there were no significant differences in C, P, Ca and Fe between treatments. Meanwhile, N and Mg were higher, whereas K concentration was lower in OTC leaves. The environmental conditions inside OTC provided a significant reduction in yield and Ravaz index of 2004, mainly due to a decrease in clusters weight. Regarding the vegetative growth parameters, OTC did not influence the pruning weight, but in 2006 the weight/shoot was significantly lower in OTC vines. In conclusion, the use OTC facility to study the impact of CO₂ enrichment was very expedite, but the extrapolation of results to the open-field environment must be prudent due to the OTC effect.

[24] LEROUX O. Collenchyma: A versatile mechanical tissue with dynamic cell walls
Annals of Botany, 2012,110(6):1083-1098.
DOI:10.1093/aob/mcs186URLPMID:22933416 [本文引用: 1]
BACKGROUND: Collenchyma has remained in the shadow of commercially exploited mechanical tissues such as wood and fibres, and therefore has received little attention since it was first described. However, collenchyma is highly dynamic, especially compared with sclerenchyma. It is the main supporting tissue of growing organs with walls thickening during and after elongation. In older organs, collenchyma may become more rigid due to changes in cell wall composition or may undergo sclerification through lignification of newly deposited cell wall material. While much is known about the systematic and organographic distribution of collenchyma, there is rather less information regarding the molecular architecture and properties of its cell walls. SCOPE AND CONCLUSIONS: This review summarizes several aspects that have not previously been extensively discussed including the origin of the term 'collenchyma' and the history of its typology. As the cell walls of collenchyma largely determine the dynamic characteristics of this tissue, I summarize the current state of knowledge regarding their structure and molecular composition. Unfortunately, to date, detailed studies specifically focusing on collenchyma cell walls have not been undertaken. However, generating a more detailed understanding of the structural and compositional modifications associated with the transition from plastic to elastic collenchyma cell wall properties is likely to provide significant insights into how specific configurations of cell wall polymers result in specific functional properties. This approach, focusing on architecture and functional properties, is likely to provide improved clarity on the controversial definition of collenchyma.

[25] ROWE N P, SPECK T. Hydraulics and mechanics of plants: Novelty, innovation and evolution
The Evolution of Plant Physiology, 2004: 297-325.
[本文引用: 1]

[26] DE WIT M, GALV?O V C, FANKHAUSER C. Light-mediated hormonal regulation of plant growth and development
Annual Review of Plant Biology, 2016,67(1):513-537.
[本文引用: 1]

[27] PROCKO C, CRENSHAW C M, LJUNG K, NOEL J P, CHORY J. Cotyledon-generated auxin is required for shade-induced hypocotyl growth in Brassica rapa
Plant Physiology, 2014,165(3):1285-1301.
URLPMID:24891610 [本文引用: 1]

[28] TAO Y, FERRER J, LJUNG K, POJER F, HONG F, LONG J A, LI L, MORENO J E, BOWMAN M E, IVANS L J, CHENG Y, LIM J, ZHAO Y, BALLARé C L, SANDBERG G, NOEL J P, CHORY J. Rapid synthesis of auxin via a new tryptophan-dependent pathway is required for shade avoidance in plants
Cell, 2008,133(1):164-176.
[本文引用: 1]

[29] DEVOGHALAERE F, THOMAS D, BAPTISTE G J K, WENDY P, TOBY J L, ROSS J J, IAN C H, KULARAJATHEVAN G, GA D, ROBERT D, KEN C B, TUSTIN D S, EVELYNE C, DAVID C, ROBERT J S A K. A genomics approach to understanding the role of auxin in apple (Malus×domestica) fruit size control
BMC Plant Biology, 2012,12:7.
DOI:10.1186/1471-2229-12-7URLPMID:22243694 [本文引用: 1]
BACKGROUND: Auxin is an important phytohormone for fleshy fruit development, having been shown to be involved in the initial signal for fertilisation, fruit size through the control of cell division and cell expansion, and ripening related events. There is considerable knowledge of auxin-related genes, mostly from work in model species. With the apple genome now available, it is possible to carry out genomics studies on auxin-related genes to identify genes that may play roles in specific stages of apple fruit development. RESULTS: High amounts of auxin in the seed compared with the fruit cortex were observed in 'Royal Gala' apples, with amounts increasing through fruit development. Injection of exogenous auxin into developing apples at the start of cell expansion caused an increase in cell size. An expression analysis screen of auxin-related genes involved in auxin reception, homeostasis, and transcriptional regulation showed complex patterns of expression in each class of gene. Two mapping populations were phenotyped for fruit size over multiple seasons, and multiple quantitative trait loci (QTLs) were observed. One QTL mapped to a region containing an Auxin Response Factor (ARF106). This gene is expressed during cell division and cell expansion stages, consistent with a potential role in the control of fruit size. CONCLUSIONS: The application of exogenous auxin to apples increased cell expansion, suggesting that endogenous auxin concentrations are at least one of the limiting factors controlling fruit size. The expression analysis of ARF106 linked to a strong QTL for fruit weight suggests that the auxin signal regulating fruit size could partially be modulated through the function of this gene. One class of gene (GH3) removes free auxin by conjugation to amino acids. The lower expression of these GH3 genes during rapid fruit expansion is consistent with the apple maximising auxin concentrations at this point.

[30] CONG L, YUE R R, WANG H B, LIU J L, ZHAI R, YANG J, WU M, SI M, ZHANG H Q, YANG C Q, XU L F, WANG Z G. 2,4-D-induced parthenocarpy in pear is mediated by enhancement of GA₄ biosynthesis
Physiologia Plantarum, 2019,166(3):812-820.
URLPMID:30203555 [本文引用: 1]

[31] SCHWECHHEIMER C. Understanding gibberellic acid signaling--are we there yet?
Current Opinion in Plant Biology, 2008,11(1):9-15.
DOI:10.1016/j.pbi.2007.10.011URLPMID:18077204 [本文引用: 1]
The phytohormone gibberellic acid (GA) controls important aspects of plant growth such as seed germination, elongation growth, and flowering. The key components of the GA signaling pathway have been identified over the past 10 years. The current view is that GA binds to a soluble GID1 receptor, which interacts with the DELLA repressor proteins in a GA-dependent manner and thereby induces DELLA protein degradation via the E3 ubiquitin ligase SCF(GID2/SLY1). GA-dependent growth responses can generally be correlated with and be explained by changes in DELLA repressor abundance, where the DELLA repressor exerts a growth restraint that is relieved upon its degradation. However, it is obvious that other mechanisms must exist that control the activity of this pathway. This review discusses recent advances in the understanding of GA signaling, of its homeostasis, and of its cross-talk with other signaling pathways.

[32] RAGHAVENDRA A S. Physiology of Trees
Published Simaltaneously in Canada, 1991: 175-178.
[本文引用: 1]

[33] ARTECA R N, TSAI D S, SCHLAGNHAUFER C, MANDAVA N B. The effect of brassinosteroid on auxin-induced ethylene production by etiolated mung bean segments
Physiologia Plantarum, 1983,59(4):539-544.
[本文引用: 1]

[34] XIONG F J, ZHUO F P, REITER R J, WANG L L, WEI Z Z, DENG K X, SONG Y, QANMBER G, FENG L, YANG Z R, LI F G, REN M Z. Hypocotyl elongation inhibition of melatonin is involved in repressing brassinosteroid biosynthesis in Arabidopsis
Frontiers in Plant Science, 2019,10:1082.
URLPMID:31616446 [本文引用: 1]

[35] 丁锦新, 马国瑞, 黄素青, 叶孟兆. 表油菜素内酯对黄瓜的生理效应
浙江农业大学学报, 1995,21(6):615-621.
[本文引用: 1]

DING J X, MA G R, HUANG S Q, YE M Z. Studies on physiological effects of epiBR on cucumber (Cucumis sativus L.)
Journal of Zhejiang Agricultural University, 1995,21(6):615-621. (in Chinese)
[本文引用: 1]