The Thermotolerance and Repair Mechanism of Photosystem in Alpine Plant Arabis paniculata (Cruciferae)

Abstract

The heat stress associated with extremely and moderately high temperatures affects a series of physiologi cal activities in plants especially photosynthesis. Howeverꎬ it is proposed that the plants use different photosynthetic strategy to deal with extreme and moderate heat stresses. Most reports focus on the cold tolerant ability but thermotol erance of alpine plants. In the present studyꎬ we used the alpine plant Arabis paniculata as a model alpine plant to examine whether its capacity for heat tolerance is exhibited under moderate heat stress andꎬ if soꎬ how this capacity is related to differences in its photosynthesis compared with that of its close relative Arabidopsis thaliana. We found that A􀆰 paniculata had high photochemical efficiency at a moderately high temperature and a rapid reversible recovery processꎬ which reflected substantial heat tolerance. Despite no obvious difference in F0 between the two speciesꎬ the higher Fm values after heat treatment and recovery in A􀆰 paniculata than in A􀆰 thaliana facilitated the rapid photo chemical recovery. A rapid and transient increase in non photochemical quenching after moderate heat stress provid ed timely protection for PSII against the damage caused by heat and light. The rapid accumulation of heat shock pro tein 101 upon exposure to moderately high temperatures might initiate photochemical repair. Finallyꎬ the high rate of survival of A􀆰 paniculata after severe heat treatment attested to the substantial heat tolerance of its photosynthetic ma chinery under moderate stress. Our results indicated that a highly heat tolerant photosystem and effective photochemi 植 物 分 类 与 资 源 学 报 2015ꎬ 37 (1): 46~54 Plant Diversity and Resources DOI: 10.7677 / ynzwyj201514037 ∗ ∗ ∗ Funding: NSFC (31300251) and XiBuZhiGuang Project Author for correspondenceꎻ E mail: weiqili@mail􀆰 kib􀆰 ac􀆰 cn Received date: 2014-03-12ꎬ Accepted date: 2014-06-11 作者简介: 唐婷 (1987-) 女ꎬ 博士ꎬ 主要从事植物逆境分子生理学研究ꎮ E mail: tangtingnkjdx@163􀆰 com cal repair mechanism contribute to the capacity of A􀆰 paniculata to tolerate moderate heat stress.