午间强光胁迫下叶黄素循环对小麦叶片光合机构的保护作用  

The Role of Xanthophyll Cycle in Protecting the Photosyn-thetic Apparatus of Wheat Leaves against Midday High Light Stress

作　　者：孟庆伟[1] 赵世杰[1] 许长成[1] 邹琦[1] 

机构地区：[1]山东农业大学,山东泰安271018

出　　处：《作物学报》1998年第6期747-750,共4页Acta Agronomica Sinica

基　　金：国家自然科学基金

摘　　要：通过测定田间小麦叶片叶黄素循环组分、光合速率和叶绿素a荧光,探讨了叶黄素循环对小麦光合机构的保护作用。晴天中午强光下叶黄素库(V+A+Z)增大,叶黄素循环三组分转化百分率(A+Z)/(V+A+Z)明显增加。弱光下无过剩光能,(A+Z)/(V+A+Z)中午不增加。用二硫苏糖醇(DTT)抑制叶黄素循环,中午强光照射2小时后光抑制加重。这些结果表明,中午前后叶黄素循环对于田间小麦叶片耗散过剩光能保护光合机构免受强光的胁迫具有重要意义。To investigate the role of the xanthophyll cycle in protecting the photosynthet- ic apparatus of wheat leaves from light stress, the carotenoid composition, photosynthetic rate and chlorophyll a fluorescence prarameter were measured. Under strong sunlight, the xanthophyll pool, namely violaxanthin + antheraxanthin+zeaxanthin (V + A + Z) and (A + Z)/(V + A + Z) increased around noon. Under weak light without excess sunlight energy, (A + Z)/(V + A + Z) did not increase during midday. Dithiothreitol (DTT) treatment reduced the (A + Z) content and exacerbated photoinhibition of photosynthesis under strong sunlight for 2 h. These results indicated that under field conditions with strong sunlight, the xanthophyll cycle can protect the photosynthetic apparatus of wheat leaves from photodamage by the increased radiationless energy dissipation.

关 键 词：叶黄素循环 光抑制 光合速率 小麦 

分 类 号：S512.101[农业科学—作物学]