【作者】 何序晨； 张志豪； 张勤； 胡伟民； 关亚静； 胡晋；

【Author】 HE Xu-Chen;ZHANG Zhi-Hao;ZHANG Qin;HU Wei-Min;GUAN Ya-Jing;HU Jin;Seed Science Center,Institute of Crop Science,College of Agriculture and Biotechnology,Zhejiang University;

【机构】 浙江大学农业与生物技术学院作物科学研究所种子科学中心；

【摘要】 高温胁迫影响玉米自交系苗期生长和制种产量,探究玉米对温度胁迫的响应机制,有利于培育和筛选抗性优良的品种。本试验在田间鉴定的基础上,选取了42份甜玉米自交系在45℃条件下进行室内抗热性鉴定和分级,并据此选用了抗热型及热敏感型自交系各两份进行生理生化指标检测和相关基因表达分析。结果表明,42份甜玉米自交系中有12份抗热型自交系、8份中等抗热型自交系、22份热敏感型白交系。经过高温胁迫处理及恢复生长后,与抗热型自交系相比,热敏感型自交系的叶绿素a、b含量、叶绿素a/b值、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、抗坏血酸过氧化酶(APX)活性、谷胱廿肽还原酶(GR)活性均下降,而脯氨酸含量小幅上升。利用qRT-PCR技术对脯氨酸合成途径的关键酶基因ZmP5CS、降解途径的关键酶基因ZmProDH、热激蛋白基因ZmHSP70和ZmHSP90在高温胁迫条件下的表达特性进行了分析,发现ZmP5CS、ZmHSP70和ZmHSP90明显受热胁迫诱导,并且热敏感型自交系中ZmP5CS、ZmHSP70和ZmHSP90的表达量均显著低于抗热型自交系,而ZmProDH的表达量显著高于抗热型自交系,由此说明,高温胁迫过程中脯氨酸的积累、抗氧化酶活性和热激蛋白基因表达的增强是玉米幼苗抗热性形成的响应机制。更多还原

【Abstract】 High temperature stress affects the growth of maize inbred lines during seedling period and seed yield,therefore it is particularly significant to study the response mechanisms of heat resistance in maize and cultivate and select high resistant varieties.Based on field evaluation,42 sweet corn inbred lines were selected for heat resistance assessment in this experiment.Two inbfed lines of heat resistant and heat sensitive typewere screened for further tests.The results showed that there were 12 heat resistant inbred lines,8 medium heat resistant inbred lines and 22 heat sensitive inbred lines in all materials.After high temperature stress and recovery growth,compared to the heat resistant inbred lines,chlorophyll a and chlorophyll b content,chlorophyll a/b value,SOD activity,POD activity,CAT activity,APX activity and GR activity were decreased in heat sensitive inbred lines,while the proline content increased slightly.The expression characteristics of ZmP5 CS and ZmProDH,the key enzyme genes of proline metabolic pathway,and heat shock protein genes ZmHSP70,ZmHSP90 under high temperature stress were analyzed by qRT-PCR.It was suggested that ZmP5 CS,ZmHSP70 and ZmHSP90 were significantly induced by heatstress,and that the expressions of these genes in heat sensitive inbred lines were significantly lower than those in heat resistant inbred lines,while the expression of ZmProDH was significantly higher.These results showed that the accumulation of proline,the activity of antioxidant enzymes and the expression of heat shock protein genes were the response mechanisms of heat resistance in maize seedlings under high temperature stress.更多还原