一氧化氮对高温与干旱复合胁迫下小麦叶片Rca基因表达及Rubisco活性的影响  

Regulating effect of nitric oxide on expression of Rca gene and activity of Rubisco in wheat leaves under combined stress of heat and drought

作　　者：杜兴良 兰盼龙 张皓帆 赵光伟[2] 李华[1] 汪月霞[1] 赵会杰[1] DU Xingliang;LAN Panlong;ZHANG Haofan;ZHAO Guangwei;LI Hua;WANG Yuexia;ZHAO Huijie(College of Life Sciences,Henan Agricultural University,Zhengzhou 450002,China;Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences,Zhengzhou 450005,China)

机构地区：[1]河南农业大学生命科学学院,河南郑州450002 [2]中国农业科学院郑州果树研究所,河南郑州450005

出　　处：《河南农业大学学报》2018年第6期868-873,共6页Journal of Henan Agricultural University

基　　金：国家自然科学基金项目(30971725)

摘　　要：以小麦(Triticum aestivum L.)品种豫麦49为材料,研究了高温、干旱及高温干旱复合胁迫对小麦叶片Ru BP羧化酶(Rubisco)、Rubisco活化酶(RCA)活性及Rubisco活化酶基因(Rca)表达的影响及外源一氧化氮(NO)的调节效应。结果表明,干旱和高温干旱复合胁迫导致小麦叶片的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性降低,而高温胁迫下SOD和CAT活性升高。NO预处理能显著增强干旱及高温干旱复合胁迫下的抗氧化酶活性。编码RCA不同亚基的基因(Rca a和Rca b)对不同逆境胁迫的响应存在差异,干旱、高温和高温干旱复合胁迫导致Rca a基因的表达水平分别降低97%,92.31%和84.93%,Rca b的转录水平则在高温和高温干旱复合胁迫下分别比对照升高了26.14和28.02倍。NO预处理使干旱胁迫下Rca a的表达增加了38.42倍,Rca b的表达增加了32.74倍,使高温干旱复合胁迫下Rca b的表达水平提高了30.39%。遭受干旱、高温及二者复合胁迫后,小麦叶片的RCA活性、Rubisco初始活性、总活性以及Rubisco活化状态明显下降,而采用NO预处理不同程度地提高了干旱、高温及高温干旱复合胁迫下小麦叶片的RCA活性及Rubisco酶的初始活性、总活性与活化状态,使其在逆境下保持较高的叶绿素含量(SPAD值)和光合速率。总之,NO能够通过增强抗氧化酶活性和调节Rca基因表达,提高RCA和Rubisco活性,缓解高温干旱复合胁迫对小麦叶片的光合作用的损伤。With“Yumai49”,a cultivar of wheat(Triticum aestivum L.),as material,studies were conducted on changes in activities of Rubisco,Rubisco activase(RCA)and expression of Rubisco activase gene(Rca)in wheat leaves under stress of heat,drought and their combination,and the regulating effects of exogenous nitric oxide(NO)were also investigated.The results showed that activities of superoxide dismutase(SOD)and catalase(CAT)in wheat leaves decreased under drought stress and cross-stress of heat and drought,but increased under heat stress.Activities of the antioxidant enzymes in leaves subjected to drought stress and cross-stress of heat and drought were significantly enhanced by pretreatment with NO.There were differences in expression of genes encoding various subunits of RCA(Rca a and Rca b)under different stress conditions.Transcription level of Rca a decreased respectively by97%、92.31%,and84.93%compared with the control under all of the stress conditions,while the expression level of Rca b increased respectively by26.14and28.02times compared with the control under heat stress and the combined stress of heat and drought.Expression of Rca a under drought stress and that of Rca b under drought stress and cross-stress of heat and drought increased by38.42times,32.74times,and30.39%pretreated with NO.RCA activity,Rubisco initial and total activity and Rubisco activation state declined apparently under all stress conditions.Exogenous NO alleviated the suppression of above-mentioned enzymes caused by drought,heat and the combined stress.Consequently,higher chlorophyll content(SPAD)and net photosynthetic rate of wheat leaves pretreated with NO were maintained under adverse conditions.In brief,NO could mitigate the damage of photosynthesis caused by cross-stress of heat and drought through enhancing antioxidant activity and regulating Rca gene expression.

关 键 词：小麦 高温干旱复合胁迫 RUBISCO活化酶 基因表达 NO调节效应 

分 类 号：S512.1[农业科学—作物学]