摘要
[目的]探讨外源2,4-表油菜素内酯(2,4-EBR)缓解芸豆幼苗盐碱胁迫伤害的生理机制,为应用2,4-EBR缓解豆类植物盐碱胁迫提供依据.[方法]以盆栽'芸选2号'幼苗为材料,研究在100 mmol/L盐碱胁迫下,喷施0.1 mg/L 2,4-EBR和4.0 mg/L油菜素内酯抑制剂芸苔素唑(BRZ)对幼苗生长、光合气体交换参数、抗氧化酶活性和渗透调节物质含量的影响.[结果]盐碱胁迫下芸豆叶片卷缩枯萎,株高、叶面积、主根长、光合色素含量、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)均显著下降(P＜0.05),脯氨酸(Pro)、可溶性糖(SS)含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性,相对电导率(REC)、丙二醛(MDA)含量和胞间 CO2浓度(Ci)显著升高.喷施2,4-EBR处理能缓解盐碱胁迫造成的叶片枯萎和卷缩,植株生长状况逐渐转好,同时有效降低幼苗叶片REC、MDA和Ci,显著提高株高、叶面积、主根长、Pro、SS、Pn、Tr、Gs及SOD、POD、CAT和APX活性,但外源2,4-EBR诱导的这些芸豆抗盐碱效应在加入BRZ后受到逆转.[结论]外源2,4-EBR处理能够提高芸豆叶片抗氧化系统酶活性和渗透调节物质含量,减轻盐碱胁迫造成的膜脂过氧化伤害及对光合作用的非气孔限制,促进幼苗生长,增强抗盐碱能力.
Abstract
[Objective]The study aims to explore the physiological mechanism of exogenous 2,4-epibrassin-olide(2,4-EBR)in alleviating the damage caused by salt-alkali stress in common bean(Phaseolus vulgaris L.)seedlings,to provide a basis for the application of 2,4-EBR to alleviate salt-alkali stress in leguminous plants.[Methods]Using Shanxi red common bean'Yunxuan 2'as the test material,the authors studied the effects of exogenous spraying of 0.1 mg/L 2,4-EBR and 4.0 mg/L brassinozole(BRZ)on the growth,photosynthetic gas parameters,antioxidant enzyme activity,and osmotic adjustment substance of common bean seedlings under saline-alkali stress at 100 mmol/L.[Results]Under saline-alkali stress,common bean leaves were curled and withered,and plant height,leaf area,main root length,synthetic pigment content,net photosynthetic rate(Pn),transpiration rate(Tr),and stomatal conductance(Gs)were all decreased significantly(P＜0.05),proline(Pro),soluble sugar(SS)content,and superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),and ascorbic acid peroxidase(APX)activities,relative con-ductivity(REC),malondialdehyde(MDA)content,and intercellular CO2 concentration(Ci)were signifi-cantly increased.Exogenous spraying of 2,4-EBR alleviated the wilting and curling of leaves caused by salt-alkali stress,and the plant growth condition was gradually improved.Meanwhile,it effectively re-duced the REC,MDA,and Ci in the leaves of the seedlings,and significantly increased plant height,leaf area,primary root length,Pro,SS,Pn,Tr,and Gs as well as SOD,POD,CAT,and APX activities.These salt-alkali resistant effects of common beans induced by exogenous 2,4-EBR were reversed by adding BRZ.[Conclusion]Exogenous 2,4-EBR treatment can reduce membrane lipid peroxidation damage caused by salt-alkali stress by increasing antioxidant system enzyme activity and osmotic adjustment sub-stance content in common bean.It effectively removes the non-stomatal limiting factors that weaken the photosynthesis of common bean seedlings under saline-alkali stress,promotes seedling growth,and en-hances the salt-alkali resistance of common bean seedlings.
国家科技期刊平台
NSTL
万方数据