A Putative Chloroplast-Localized Ca2＋/H＋ Antiporter CCHA1 Is Involved in Calcium and pH Homeostasis and Required for PSII Function in Arabidopsis

作     者：Chao Wang Weitao Xu Honglei Jin Taijie Zhang Jianbin Lai Xuan Zhou Shengchun Zhang Shengjie Liu Xuewu Duan Hongbin Wang Changlian Peng Chengwei Yang 

作者机构：Guangdong Key Lab of Biotechnology for Plant Development College of Life Science South China Normal University Guangzhou 510631 China State Key Laboratory of Biocontrel and Guangdeng Key Laboratory of Plant Resources School of Life Sciences Sun Yat-sen University Guangzhou 510275 China Key Laboratory of Plant Resource Conservation and Sustainable Utilization South Ohina Botanical Garden Chinese Academy of Sciences Guangzheu Guangdong Province 510650 China 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2016年第9卷第8期

页      面：1183-1196页

核心收录：

学科分类：0710[理学-生物学] 071001[理学-植物学] 07[理学] 

基　　金：国家自然科学基金 Guangdong Provincial Department of Science and Technology the Key Program from the Department of Education of Guangdong Province (2015) 

主　　题：Ca2+/H+ antiporter Ca2+ homeostasis pH homeostasis CCHA1 

摘      要：Calcium is important for chloroplast, not only in its photosynthetic but also nonphotosynthetic functions. Mul- tiple Ca2＋/H＋ transporters and channels have been described and studied in the plasma membrane and organ- elle membranes of plant cells; however, the molecular identity and physiological roles of chloroplast Ca2＋/H＋ antiporters have remained unknown. Here we report the identification and characterization of a member of the UPFO016 family, CCHA1 （a chloroplast-localized potential Ca2＋/H＋ antiporter）, in Arabidopsis thaliana. We observed that the ccha I mutant plants developed pale green leaves and showed severely stunted growth along with impaired photosystem II （PSII） function. CCHA1 localizes to the chloroplasts, and the levels of the PSII core subunits and the oxygen-evolving complex were significantly decreased in the ccha I mutants compared with the wild type. In high Ca2＋ concentrations, Arabidopsis CCHA1 partially rescued the growth defect of yeast gdtl3 null mutant, which is defective in a Ca2＋/H＋ antiporter. The cchal mutant plants also showed significant sensitivity to high concentrations of CaCI2 and MnCI2, as well as variation in pH. Taken these results together, we propose that CCHA 1 might encode a putative chloroplast-localized Ca2＋/H＋ antiporter with critical functions in the regulation of PSII and in chloroplast Ca2＋ and pH homeostasis in Arabidopsis.