几内亚格木和降香黄檀对热带北缘地区冬季低温的光合适应(英文)  

Photosynthetic Acclimation of Erythrophleum guineense and Dalbergia odorifera to Winter Low Temperature in a Marginal Tropical Area

作　　者：黄伟[1,2] 曹坤芳[2] 

机构地区：[1]中国科学院昆明植物研究所资源植物与生物技术重点实验室,云南昆明650201 [2]中国科学院西双版纳热带植物园热带森林生态学重点实验室,云南勐腊666303

出　　处：《植物分类与资源学报》2014年第3期310-320,共11页Plant Diversity

基　　金：National Natural Science Foundation of China (grant 30900174)

摘　　要：在热带北缘地区,冬季气温较夏季下降10℃左右,虽然热带植物对零上低温敏感,但是大部分热带树木能够适应热带北缘地区的冬季气温,其光合生理机制并不清楚。我们通过测定种植在热带北缘地区(21°54'N,101°46'E)的两种热带树木(几内亚格木和降香黄檀)的光系统I和II活性以及光系统I和II的能量分配的季节变化,发现这两个树种的光系统I和II活性在冬季并没有下降。两个树种的光系统II的有效量子产额在冬季明显下降,同时伴随着热耗散激发。在冬季,环式电子传递的激发与热耗散的激发呈现显著的正相关。环式电子传递的激发使得氧化态P700比例的上升,从而避免了光系统I受体端的过度还原。化学试剂抗霉素A(PGR5途径环式电子传递的一种特异性抑制剂)处理过的叶片较对照组表现出更强光损伤程度。这些结果表明环式电子传递的激发是热带树木适应热带北缘地区冬季低温的一个重要的光合生理机制。In marginal tropical areas, air temperature in winter usually decreases by 10 ℃ compared with summer at night/day. Although tropical plants are sensitive to low temperature, the mechanism underlying photosynthetic acclimation of tropical trees to winter low temperature is unclear. To address this question, the photosystem Ⅰ （PSⅠ） and photosystem Ⅱ （PSⅡ） activities, and energy distribution in PSI and PSⅡ were examined in summer and winter in two tropical high-quality timber tree species Erythrophleum guineense and Dalbergia odorifera grown in a marginal tropical area （21°54′N,101°46′E）. Our resuhs indicated that the photosynthetic apparatus of E. guineense and D. odorifera was maintained stable in winter. The effective quantum yield of PSⅡ decreased significantly in winter, but non-photochemical quenching （NPQ） significantly increased. In winter, cyclic electron flow （CEF） was significantly stimulated in both species, which was significantly and positively correlated with NPQ. Meanwhile, the stimulation of CEF led to an increase in P700 oxidation ratio and the over-reduction of PSI acceptor side was prevented.Antimycin A （ a specific inhibitor of PGR5-dependent CEF） significantly aggravated PSⅡ photoinhibition under high light in both species. These results suggested that stimulation of CEF is an important mechanism for photosynthetic acclimation to winter low temperature in a marginal tropical area in the two tropical tree species.

关 键 词：适应 环式电子传递 冬季 光系统I 光系统I 热带树木 

分 类 号：Q945.11[生物学—植物学]