Aluminum-Enhanced Proton Release Associated with Plasma Membrane H^+-Adenosine Triphosphatase Activity and Excess Cation Uptake in Tea (Camellia sinensis) Plant Roots

作     者：WAN Qing MI Yuhe YANG Yiyang Xu Renkou LI Xinghui 

作者机构：Tea Research InstituteNanjing Agriculture University Institute of Leisure AgricultureJiangsu Academy of Agricultural Sciences State Key Laboratory of Soil and Sustainable AgricultureInstitute of Soil ScienceChinese Academy of Sciences 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2018年第28卷第5期

页      面：804-813页

核心收录：

学科分类：09[农学] 0903[农学-农业资源与环境] 090203[农学-茶学] 0902[农学-园艺学] 090301[农学-土壤学] 

基　　金：supported by the National Natural Science Foundation of China (Nos. 31600558 and 31400587) the Natural Science Foundation of Jiangsu, China (No. BK20160590) the Earmarked Fund for Modern Agro-industry Technology Research System of China (No. CARS-19) the Agricultural Science and Technology Innovation Fund of Jiangsu, China (No. CX(13)5016) 

主　　题：acidification aluminum toxicity cation-anion balance nutrient accumulation plant uptake rhizosphere soil acidity 

摘      要：Cultivated tea(Camellia sinensis) plants acidify the rhizosphere, and Aluminum(Al) toxicity is recognized as a major limiting factor for plant growth in acidic soils. However, the mechanisms responsible for rhizosphere acidification associated with Al have not been fully elucidated. The present study examined the effect of Al on root-induced rhizosphere acidification, plasma membrane H^+-adenosine triphosphatase(H^+-ATPase) activity, and cation-anion balance in tea plant roots. The exudation of H^+from tea plant roots with or without Al treatment was visualized using an agar sheet with bromocresol purple. The H^+-ATPase activity of plasma membranes isolated from the roots was measured after hydrolysis using the two-phase partition system. The Al treatment strongly enhanced the exudation of H^+, and the acidification of tea plant roots by Al was closely associated with plasma membrane H^+-ATPase activity. The root plasma membrane H^+-ATPase activity increased with Al concentration. The Al content, amount of protons released, and H^+-ATPase activity were significantly higher in roots treated with Al than in those untreated. The results of the cation-anion balance in roots showed an excess of cations relative to anions, with the amount of excess cation uptake increasing with increasing Al concentrations. These suggest that Al-enhanced proton release is associated with plasma membrane H^+-ATPase activity and excess cation uptake. Findings of this study would provide insights into the contributing factors of soil acidification in tea plantations.