As an important successional stage of biological soil crusts, lichen soil crusts (LSCs) are often in the dry and inactive state in desert environments, so it is vital for their survival and development in these areas to reactivate the photosynthetic systems during a rehydration event. In this study, the reactivation patterns of light-harvesting complexes (LHCs) and reaction centres of photosystem (PS) II in the long-term desiccated LSCs (approximately 10 months) were monitored using chlorophyll a fluorescence technique. For the long-term desiccated LSCs, PS II reaction centres could recover their activity gradually in the light after rehydration, whereas no obvious recovery occurred in the dark (0.1 < Fv/Fm < 0.2). After experiencing prior rehydration/desiccation (R/D) cycle(s) in the light, the PS II reaction centres could rapidly recover their activity following rehydration both in the light and dark. Even the most reactivation (76 % of the PSII centers) was independent on the synthesis of new proteins. In addition, compared with reaction centres, LHCs of PS II could recover their activity faster both in the light and dark, and prior R/D cycle(s) also accelerated the recovery of LHC II. It is concluded that prior R/D cycles strongly accelerated LSC recovery process of photosynthetic systems and removed the dependence on light in subsequent hydration events. This characteristic is essential for LSCs to survive and develop in desert environments because it facilitates more carbon fixation during transient rehydration.
英文摘要:
As an important successional stage of biological soil crusts, lichen soil crusts (LSCs) are often in the dry and inactive state in desert environments, so it is vital for their survival and development in these areas to reactivate the photosynthetic systems during a rehydration event.
1.Chinese Acad Sci, Inst Hydrobiol, Key Lab Algal Biol, Wuhan 430072, Peoples R China 2.Chinese Acad Sci, Grad Sch, Beijing 100039, Peoples R China 3.Wuhan Univ Technol, Dept Biol Sci & Biotechnol, Wuhan 430070, Peoples R China
Recommended Citation:
Wu, Li; Lan, Shubin; Zhang, Delu; Hu, Chunxiang.Functional reactivation of photosystem II in lichen soil crusts after long-term desiccation,PLANT AND SOIL,2013,369(41276):177-186
