低氧胁迫下黄瓜植株热耗散途径  

Thermal dissipation pathway in cucumber seedling leaves under hypoxia stress.

作　　者：贾永霞[1,2,3] 孙锦[1,2] 王丽萍[1,2] 束胜[1,2] 郭世荣[1,2] 

机构地区：[1]南京农业大学园艺学院,南京210095 [2]农业部南方蔬菜遗传改良重点开放实验室,南京210095 [3]四川农业大学资源环境学院,四川雅安625014

出　　处：《应用生态学报》2011年第3期707-712,共6页Chinese Journal of Applied Ecology

基　　金：国家重点基础研究发展计划项目(2009CB119000);国家自然科学基金项目(30871736;31071831);现代农业产业技术体系建设专项(Nycytx-35-gw18)资助

摘　　要：采用营养液栽培,研究了低氧(营养液溶氧浓度为0.9～1.1 mg.L-1)胁迫下黄瓜幼苗光合作用热耗散与叶黄素循环的关系.结果表明:低氧胁迫下,黄瓜叶片PSⅡ的实际光化学效率(ΦPSⅡ)、饱和光强下的净光合速率(Pn)、表观量子效率(AQY)和PSⅡ的最大光化学效率(Fv/Fm)均显著降低,表明黄瓜植株的光合作用受到了光抑制;同时,光化学猝灭系数(qP)降低,而热耗散(NPQ)和天线耗散能量(D)的比值显著升高,说明黄瓜叶片热耗散增强;NPQ与叶黄素脱环氧化状态(DEPS)呈显著正相关,且两者均被抗坏血酸(AsA)所促进,被二硫苏糖醇(DTT)所抑制,说明低氧胁迫下,叶黄素循环是黄瓜植株光合作用热耗散的主要途径.A water culture experiment was conducted to study the relationship between photosynthetic thermal dissipation and xanthophyll cycle in cucumber seedling leaves under hypoxia stress（the dissolved oxygen concentration in nutrient solution was 0.9-1.1 mg·L-1）.Under the hypoxia stress,there was a significant decrease in the quantum yield of PSⅡ photochemistry rate（ΦPSⅡ）,net photosynthetic rate（Pn） under saturation light intensity,quanta yield（AQY）,and maximal photochemical efficiency（Fv/Fm）,suggesting that the photoinhibition of the seedling leaves was induced.Meanwhile,the thermal dissipation（NPQ） and the allocation of dissipation energy（D） by antenna increased,but the photochemical quenching apparent（qP） decreased,suggesting the enhancement of thermal dissipation in cucumber leaves under hypoxia stress.A positive correlation was observed between NPQ and xanthophyll de-epoxidation state（DEPS）,and both of them were promoted by ascorbic acid（AsA） and inhibited by 1,4-dithiothreitol（DTT）,suggesting that xanthophyll cycle was the major pathway of photosynthetic thermal dissipation in cucumber seedling leaves under hypoxia stress.

关 键 词：低氧胁迫 黄瓜 光抑制 叶黄素循环 

分 类 号：S642.2[农业科学—蔬菜学]