小苍兰幼苗对高温胁迫的生理响应  

Physiological Responses of Freesia hybrida Seedlings to High Temperature Stress

作　　者：袁媛[1] 唐东芹[1] 史益敏[1] 

机构地区：[1]上海交通大学农业与生物学院,上海200240

出　　处：《上海交通大学学报（农业科学版）》2011年第5期30-36,共7页Journal of Shanghai Jiaotong University(Agricultural Science)

基　　金：国家自然科学基金项目(30872061)

摘　　要：以小苍兰品种"上农金皇后"15d幼苗为实验材料,测定其叶片在30℃高温胁迫144h期间的生理指标变化。结果表明:高温胁迫期间,幼苗叶片中的叶绿素含量不断下降,胁迫结束时叶绿素含量显著低于对照;细胞膜透性(EL)、丙二醛(MDA)含量显著升高,脯氨酸随胁迫不断积累;可溶性糖含量在高温胁迫前6h里轻微下降,然后持续上升至胁迫结束;超氧阴离子自由基(O2.-)释放速率在高温胁迫前2h里上升,然后持续下降,72h后接着持续上升至胁迫结束;抗氧化酶系统在高温胁迫期间积级响应,以消除各活性氧(ROS)。超氧化物歧化酶(SOD)活性的变化与O2.-释放速率的变化模式对应,在高温胁迫前2h里下降,然后显著上升,从72h开始下降至胁迫结束;过氧化氢酶(CAT)和过氧化物酶(POD)活性的变化模式相似,胁迫前期轻微下降,然后持续显著增加;抗坏血酸过氧化物酶(APX)活性在高温胁迫期间显著持续上升,活性明显高于对照。以上研究结果为在高温地区栽培小苍兰提供了理论基础。Fifteen-day-old seedlings of Freesia hybrida Shangnong Jinhuanghou＇ were exposed to 30 ℃ for 144 h to investigate the physiological response to high temperature stress.The results showed that high temperature stress causes a significant decrease in chlorophylls content and a significant increase in malondialdehyde（MDA） content and electrolytic leakage（EL） in Freesia seedlings.Under high temperature stress,accumulation in proline content was observed,while a slight decrease in soluble sugar content occurred in the first 6 h exposure to stress,followed by a constant increase.Superoxide radical（O·-2） producing rate increases in the first 2 h exposure and then significantly decreases up to 72 h,followed by an increase at the end of stress.Antioxidant enzymes were triggered to scavenge reactive oxygen species（ROS） under high temperature stress.The change pattern of superoxide dismutase（SOD） activity is exactly contrary to that of O·-2 producing rate.SOD activity decreased in the first 2 h exposure,followed by a significant increase up to 72 h and then decreased at 144 h.Catalase（CAT） and peroxidase（POD） activities showed a similar change pattern：a significant increase after an early short-term decrease under high temperature stress.For ascorbate peroxidase（APX）,high temperature caused a constant increase and a significant higher level of APX activities than control in treated Freesia seedlings.These results provided further physiological basis for the Freesia cultivation,especially in high temperature regions.

关 键 词：小苍兰 高温胁迫 叶绿素 渗透调节物质 抗氧化酶 活性氧 

分 类 号：S682.29[农业科学—观赏园艺]