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.
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.
Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA.
Rongbin
0000-0001-5921-6891
R
Hu
Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA.
Yinfeng
Y
Zhu
Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, 310027, China.
Jia
J
Wei
Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA.
Jian
J
Chen
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79409, USA.
Huazhong
H
Shi
Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, 310027, China.
Guoxin
G
Shen
Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA.
Hong
H
Zhang
D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D018118:Chloride Channels / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D009154:Mutation / Q000235:genetics; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development*; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development*; D030821:Plants, Genetically Modified; D011485:Protein Binding / Q000187:drug effects; D054648:Protein Phosphatase 2 / Q000235:genetics / Q000378:metabolism*; D015203:Reproducibility of Results; D015398:Signal Transduction / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology*; D020798:Two-Hybrid System Techniques; D015854:Up-Regulation / Q000187:drug effects
D029681:Arabidopsis Proteins; D018118:Chloride Channels; D012965:Sodium Chloride; C000625307:PP2A protein, Arabidopsis; D054648:Protein Phosphatase 2
chloride channel; salt signalling; salt tolerance