Acclimatory responses to high-salt stress in Chlamydomonas （Chlorophyta, Chlorophyceae） from Antarctica

• Published in: 海洋学报：英文版 Vol. 31; no. 1; pp. 116 - 124
• Main Author: KAN Guangfeng SHI Cuijuan WANG Xiaofei XIE Qiuju WANG Min WANG Xinlei MIAO Jinlai
• Format: Journal Article
• Language: English
• Published: 2012
• Subjects: 单不饱和脂肪酸; 南极洲; 压力; 多不饱和脂肪酸; 绿藻; 自由基诱导; 超氧化物歧化酶活性; 高盐度
• ISSN: 0253-505X; 1869-1099

Antarctic ice microalga can survive and thrive in channels or pores containing high salinity in Antarctic ice layer. In this study, it was found that cell membrane permeability of green microalga Chlaraydomonas sp. L4 from Antarctic sea ice was high in cells treated with hypersalinity due to the induction of active oxygen and radicals. However, increased super oxide dismutase （SOD） scavenged harmful free radicals effectively to keep cell membrane integrity. Also, the analysis of membrane fatty acids demonstrated the content of saturated fatty acids and monounsaturated fatty acids in- creased and polyunsaturated fatty acids decreased under the high-salt treatment for 14 d, which effectively reduced the membrane fluidity and minimized the injury to cell membrane. The morpho- logical changes showed that hypersalinity induced the increase of cell volume and the consumption of starch granules. However, because of the increase in detoxification of vacuoles, electron-dense deposits and SOD activity under high-salt stress, the complete noninterference thylakoids, mito- chondria and cell nucleus maintained cellular fundamental metabolism. Global-expression profiling of proteins showed eight protein spots disappeared, 18 protein spots decreased and 18 protein spots were enhanced after the high-salt shock obviously （P 〈0.05）. One new peptide （pI 6.90; MW 51 kDa） was primarily confirmed as the processor of light reaction center protein CP43 in photosystem II, which increased photosynthesis ability of Chlamydomonas sp. L4 treated with high salinity.