喷施茉莉酸对铝胁迫紫花苜蓿光合系统的影响  

Effect of jasmonic acid on photosynthetic system of alfalfa(Medicago sativa L.)under aluminum stress

作　　者：方婷玉 程晓晴 周鹏[1] 王伟荣[2] 安渊[1,3] FANG Ting-yu;CHENG Xiao-qing;ZHOU Peng;WANG Wei-rong;AN Yuan(School of Agriculture and Biology,Shanghai Jiaotong University,Shanghai 200240,China;Shanghai Academy of Agricultural Sciences,Shanghai 201106,China;Key Laboratory of Urban Agriculture,Ministry of Agriculture,Shanghai 200240,China)

机构地区：[1]上海交通大学农业与生物学院,上海200240 [2]上海市农业科学院,上海201106 [3]农业部都市农业重点实验室,上海200240

出　　处：《上海交通大学学报（农业科学版）》2019年第6期46-53,共8页Journal of Shanghai Jiaotong University(Agricultural Science)

基　　金：国家重点研发计划项目(2017YFD0502105);国家自然科学基金(31572451);上海市农委重点项目[沪农科种字(2017)第1-3号]。

摘　　要：通过外源喷施不同浓度茉莉酸(5、25、50μmol/L),研究了茉莉酸对铝胁迫下紫花苜蓿幼苗生长和光合特性的影响。结果表明,100μmol/L AlCl 3处理使得紫花苜蓿生长受到抑制,其叶绿素含量下降,叶片的光合速率、气孔导度和蒸腾速率降低,光系统I(PSI)和光系统II(PSII)的相对电子传导速率、P700活性和环式电子传递量(CEF)也明显降低。外源喷施低浓度茉莉酸(~5μmol/L)对缓解苜蓿铝毒害的作用最为显著。外源喷施低浓度茉莉酸(5μmol/L)时,苜蓿根长、地上和地下生物量明显高于铝胁迫处理,同时叶绿素含量、光合速率、气孔导度和蒸腾速率明显升高;PSI和PSII的相对电子传导速率、P700活性和CEF值显著增加。而喷施过高浓度茉莉酸(~50μmol/L)对铝胁迫下紫花苜蓿的生长无明显缓解作用。研究结果表明低浓度茉莉酸对苜蓿铝毒害的缓解作用与茉莉酸改善铝胁迫苜蓿的光合作用和光化学系统电子传递能力密切相关。The effects of exogenous application of jasmonic acid(5,25 and 50μmol/L)on the growth and photosynthetic characteristics of alfalfa seedlings under aluminum stress were studied.The results showed that the growth rate of alfalfa was markedly inhibited under 100μmol/L AlCl 3.The chlorophyll contents,photosynthetic rate,stomatal conductance and transpiration rate were reduced.The relative electron conduction rates of photosystem I(PSI)and photosystem II(PSII),P700 activity and cyclic electron flow(CEF)were reduced as well.Exogenous application of low concentration jasmonic acid(~5μmol/L)significantly alleviated the aluminum toxicity on alfalfa.Root length,aboveground and underground biomass were significantly enhanced by jasmonic acid(5μmol/L)treatment.The chlorophyll content,photosynthetic rate,stomatal conductance and transpiration rate significantly increased.The relative electron conduction rate,P700 activity and CEF value of PSI and PSII was improved.However,exogenous application of high concentration jasmonic acid(~50μmol/L)did not alleviate the growth inhibition effect of aluminum on alfalfa.These results indicated that the reduced aluminum toxicity in alfalfa caused by exogenous application of jasmonic acid with low concentration was closely related to the improvements of photosynthetic and electron transport abilities under aluminum stress.

关 键 词：茉莉酸 铝胁迫 紫花苜蓿 光合系统 

分 类 号：S541.9[农业科学—作物学]