外源褪黑素与钙离子互作对高温胁迫下黄瓜幼苗过氧化伤害的缓解效应  

Alleviating effect of exogenous melatonin and calcium on the peroxidation damages of cucumber under high temperature stress.

作　　者：徐晨潇 张晓宇 刘超越 刘昆 毕焕改[1] 艾希珍[1] XU Chen-xiao;ZHANG Xiao-yu;LIU Chao-yue;LIU Kun;BI Huan-gai;AI Xi-zhen(College of Horticulture Science and Engineering,Shandong Agricultural University/State Key Laboratory of Crop Biology/Key Laboratory of Horticultural Crop Biology and Germplasm Innovation in Huanghuai Region,Ministry of Agriculture/Collaborative Innovation Center of Shandong Province with High Quality and Efficient Production of Fruit and Vegetable,Tai’an 271018,Shandong,China)

机构地区：[1]山东农业大学园艺科学与工程学院/作物生物学国家重点实验室/农业部黄淮地区园艺作物生物学与种质创制重点开放实验室/山东果蔬优质高效生产协同创新中心,山东泰安271018

出　　处：《应用生态学报》2022年第10期2725-2735,共11页Chinese Journal of Applied Ecology

基　　金：国家重点研发计划项目(2018YFD1000800);山东省重大科技创新工程项目(2019JZZY010715);山东省现代农业产业技术体系建设专项(SDAIT-05-10)资助。

摘　　要：为了探明褪黑素(MT)和钙离子(Ca^(2+))在调控植物耐热性中是否存在互作关系,以黄瓜幼苗为试材,分析了内源MT和Ca^(2+)对高温胁迫的响应;并通过叶面喷施100μmol·L^(-1)MT、10 mmol·L^(-1)CaCl_(2)、3 mmol·L^(-1)乙二醇二乙醚二胺四乙酸(EGTA,Ca^(2+)螯合剂)+100μmol·L^(-1)MT、0.05 mmol·L^(-1)氯丙嗪(钙调素拮抗剂,CPZ)+100μmol·L^(-1)MT、100μmol·L^(-1)氯苯丙氨酸(p-CPA,MT合成抑制剂)+10 mmol·L^(-1)CaCl_(2)和去离子水(H_(2)O),研究高温下(42/32℃)外源MT和Ca^(2+)对黄瓜幼苗活性氧积累、抗氧化系统及热激转录因子(HSF)和热激蛋白(HSPs)等的影响。结果表明:黄瓜幼苗内源MT和Ca^(2+)均受高温胁迫诱导;外源MT可上调常温下钙调素蛋白(CaM)、钙依赖蛋白激酶(CDPK5)、钙调磷酸酶B类蛋白(CBL3)、CBL结合蛋白激酶(CIPK2)mRNA表达;CaCl_(2)处理的MT合成关键基因色氨酸脱羧酶(TDC)、5-羟色胺-N-乙酰转移酶(SNAT)和N-乙酰-5-羟色胺甲基转移酶(ASMT)水平也显著升高,MT含量快速增加。MT和CaCl_(2)可显著增强高温下黄瓜的抗氧化能力,减少活性氧(ROS)积累,同时上调HSF7、HSP70.1和HSP70.11 mRNA表达,从而减轻高温胁迫引起的过氧化伤害,植株热害症状明显减轻,热害指数和电解质渗漏率显著降低。加入EGTA和CPZ后,MT对黄瓜幼苗抗氧化能力和热激蛋白表达的促进效应明显减弱,Ca^(2+)对高温下黄瓜幼苗过氧化伤害的缓解效应也被p-CPA逆转。可见,MT和Ca^(2+)均可诱导黄瓜幼苗的耐热性,二者在热胁迫信号转导过程中存在互作关系。To explore whether there is an interaction between melatonin(MT)and calcium(Ca^(2+))in regulating heat tolerance of plants,we analyzed the response of endogenous MT and Ca^(2+)to heat stress,and examined the effect of MT and Ca^(2+)on the reactive oxygen(ROS)accumulation,antioxidant system,and transcripts of heat shock factor(HSF)and heat shock proteins(HSPs)of cucumber seedlings under high temperature stress.Seed-lings were foliar sprayed with 100μmol·L^(-1)MT,10 mmol·L^(-1)CaCl_(2),3 mmol·L^(-1)ethylene glycol tetraacetic acid(EGTA,Ca^(2+)chelating agent)+100μmol·L^(-1)MT,0.05 mmol·L^(-1)chlorpromazine(calmodulin antago-nist,CPZ)+100μmol·L^(-1)MT,100μmol·L^(-1)p-chlorophenylalanine(p-CPA,inhibitor of MT)+10 mmol·L^(-1)CaCl_(2)or deionized water(H_(2) O),respectively.The results showed that both endogenous MT and Ca^(2+)in cucumber seedlings were induced by high temperature stress.The seedlings treated with exogenous MT showed sig-nificant increases in the mRNA expression of calmodulin(CaM),calcium-dependent protein kinase(CDPK5),calcineurin B-like protein(CBL3)and CBL interacting protein kinase(CIPK2)compared with the control at normal temperature.The mRNA levels of tryptophane decarboxylase(TDC),5-hydroxytryptamine-N-acetyltransferase(SNAT)and N-acetyl-5-hydroxytryptamine methyltransferase(ASMT),key genes of MT biosynthesis and endoge-nous MT content were also induced by Ca^(2+)in cucumber seedlings.Exogenous MT and CaCl_(2)alleviated the heat-induced oxidative damage through increasing antioxidant ability,reducing the accumulation of reactive oxygen spe-cies(ROS),and upregulating the mRNA abundances of HSF7,HSP70.1 and HSP70.11,as evidenced by mild thermal damage symptoms,lower heat injury index and electrolyte leakage under heat stress.The positive effect of MT-induced antioxidant capacity and mRNA expression of HSPs was removed by adding EGTA and CPZ in stressed seedlings.Similarly,the mitigating role of Ca^(2+)in the peroxidation damage to high temperature stress was reversed by p-CPA.These res

关 键 词：褪黑素 钙离子 活性氧 抗氧化系统 高温胁迫 黄瓜 

分 类 号：S642.2[农业科学—蔬菜学]