Calcium pretreatment increases thermotolerance of Laminaria japonica sporophytes  

作　　者：You Wang Qingyun Yu Xuexi Tang Lili Wang 

机构地区：[1]College of Marine Life Sciences, Ocean University of China, No. 5 Yushan Road, Qingdao 266003, China

出　　处：《Progress in Natural Science:Materials International》2009年第4期435-442,共8页自然科学进展·国际材料（英文版）

基　　金：supported by Opening Foundation of Key Laboratory of Coastal Sea Ecology and Environment,National Maritime Bureau;the National Natural ScienceFoundation of China (Grant No. 30270258);Program for New Century Excellent Talents in University (Grant No. NCET 05-0597)

摘　　要：Calcium is a secondary messenger in plant signaling, and its concentration changes spatially and temporally during the course of heat stress. In the present study, potassium antimonate was used to visualize calcium localization in blades of a marine macroalga, the juvenile Laminariajaponiea sporophytes under heat stress （25 ℃）. Result showed that loosely bound calcium was mainly distributed on the cell wall under normal conditions （10 ℃）, and flowed into the cytoplasm when exposed to heat. The simutaneous assay on the antioxidant system changes was performed. Oxidative damage, as measured by generation of reactive oxygen species （ROS） malondialdehyde （MDA） content, increased significantly during heat stress, and calcium pretreatment alleviated oxidative damage. The assay on the activities of six antioxidant enzymes demonstrated that their enzymatic activities were inhibited when exposed to heat stress, but Ca^2＋ pre- treatment effectively attenuated the inhibition. Results in the present study inferred that calcium homeostasis plays an essential role in L. japonica sporophyte when exposed to heat, and calcium pretreatment could improve its thermo-tolerance.Calcium is a secondary messenger in plant signaling, and its concentration changes spatially and temporally during the course of heat stress. In the present study, potassium antimonate was used to visualize calcium localization in blades of a marine macroalga, the juvenile Laminaria japonica sporophytes under heat stress (25 °C). Result showed that loosely bound calcium was mainly distributed on the cell wall under normal conditions (10 °C), and flowed into the cytoplasm when exposed to heat. The simutaneous assay on the antioxidant system changes was performed. Oxidative damage, as measured by generation of reactive oxygen species (ROS) malondialdehyde (MDA) content, increased significantly during heat stress, and calcium pretreatment alleviated oxidative damage. The assay on the activities of six antioxidant enzymes demonstrated that their enzymatic activities were inhibited when exposed to heat stress, but Ca2+ pretreatment effectively attenuated the inhibition. Results in the present study inferred that calcium homeostasis plays an essential role in L. japonica sporophyte when exposed to heat, and calcium pretreatment could improve its thermo-tolerance.

关 键 词：Calcium localization Calcium pretreatment Heat stress Antioxidant enzyme Laminaria japonica sporophyte 

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