Overexpression of PP2A-C5 that encodes the catalytic subunit 5 of protein phosphatase 2A in Arabidopsis confers better root and shoot development under salt conditions

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• 作者：Rongbin Hu ; Yinfeng Zhu ; Jia Wei ; Jian Chen ; Huazhong Shi ; Guoxin Shen and Hong Zhang
• 刊名：Plant, Cell & Environment
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：40
• 期：1
• 页码：150-164
• 全文大小：1361K
• ISSN：1365-3040

文摘

Protein phosphatase 2A (PP2A) is an enzyme consisting of three subunits: a scaffolding A subunit, a regulatory B subunit and a catalytic C subunit. PP2As were shown to play diverse roles in eukaryotes. In this study, the function of the Arabidopsis PP2A-C5 gene that encodes the catalytic subunit 5 of PP2A was studied using both loss-of-function and gain-of-function analyses. Loss-of-function mutant pp2a-c5-1 displayed more impaired growth during root and shoot development, whereas overexpression of PP2A-C5 conferred better root and shoot growth under different salt treatments, indicating that PP2A-C5 plays an important role in plant growth under salt conditions. Double knockout mutants of pp2a-c5-1 and salt overly sensitive (sos) mutants sos1-1, sos2-2 or sos3-1 showed additive sensitivity to NaCl, indicating that PP2A-C5 functions in a pathway different from the SOS signalling pathway. Using yeast two-hybrid analysis, four vacuolar membrane chloride channel (CLC) proteins, AtCLCa, AtCLCb, AtCLCc and AtCLCg, were found to interact with PP2A-C5. Moreover, overexpression of AtCLCc leads to increased salt tolerance and Cl⁻ accumulation in transgenic Arabidopsis plants. These data indicate that PP2A-C5-mediated better growth under salt conditions might involve up-regulation of CLC activities on vacuolar membranes and that PP2A-C5 could be used for improving salt tolerance in crops.