标题：The response of carbohydrate metabolism to the fluctuation of relative humidity (RH) in the desert soil cyanobacterium Phormidium tenue
作者：Chen, LZ(Chen, Lanzhou);Yang, Y(Yang, Yan);Deng, SD(Deng, Songdiang);Xu, YH(Xu, Yanhong);Wang, GH(Wang, Gaohong);Liu, YD(Liu, Yongding)
来源出版物：EUROPEAN JOURNAL OF SOIL BIOLOGY 卷：48 页：11-16 出版年：JAN-FEB 2012
摘要：The excreting of exopolysaccharides (EPS) is thought as one of the main protection ways for cyanobacteria in desert algal crusts to survive desiccation. But how cyanobacteria adjust their carbohydrate metabolism to survive this stress is not elucidated. In this study, we treated Phormidium tenue, a cyanobacterium isolated from biological soil crusts with the changes of relative humidity (RH) to simulate different levels of desiccation and investigated its carbohydrate metabolism. It was found that photosynthetic activity (Fv/Fm) and cellular total carbohydrates production decreased significantly at low RH. But the production of EPS, reducing sugar, sucrose and the activity of sucrose phosphate synthase (SPS) increased significantly at low RH and reached maximum at 75% RH. Low RH could also cause the enhanced production of reactive oxygen species (ROS) generation, malondialdehyde (MDA) production and DNA strand breaks. However, when pretreated with exogenous 100 mg/L EPS, Fv/Fm and carbohydrate production were improved significantly, while ROS generation, MDA production and DNA strand breaks decreased significantly at various levels of RH in P tenue. These results indicated that P. tenue in arid regions could enhance desiccation tolerance by adjusting the carbohydrate metabolism to eliminate ROS and decrease oxidative damage.
作者关键词：Biological soil crusts; Exoplysaccharides (EPS); Desiccation; Oxidative damage
扩展关键词：DESICCATION TOLERANCE; MICROCOLEUS-VAGINATUS; OXIDATIVE DAMAGE; SALT STRESS; DNA-DAMAGE; EXOPOLYSACCHARIDES; CRUSTS; POLYSACCHARIDES; PHOTOSYNTHESIS; INVOLVEMENT
通讯作者地址：Chen, LZ (通讯作者),Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Peoples R China
[Chen, Lanzhou; Yang, Yan; Deng, Songdiang; Xu, Yanhong]Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Peoples R China
[Wang, Gaohong; Liu, Yongding]Chinese Acad Sci, State Key Lab Freshwater Ecol & Biotechnol, Inst Hydrobiol, Wuhan 430072, Peoples R China
学科类别：Environmental Sciences & Ecology; Agriculture
