Interactions between soybean ABA receptors and type 2C protein phosphatases.
The plant hormone abscisic acid (ABA) plays important roles in regulating plant growth, development, and responses to environmental stresses. Proteins in the PYR/PYL/RCAR family (hereafter referred to as PYLs) are known as ABA receptors. Since most studies thus far have focused on Arabidopsis PYLs, little is known about PYL homologs in crop plants. We report here the characterization of 21 PYL homologs (GmPYLs) in soybean. Twenty-three putative GmPYLs can be found from soybean genome sequence and categorized into three subgroups. GmPYLs interact with AtABI1 and two GmPP2Cs in diverse manners. A lot of the subgroup I GmPYLs interact with PP2Cs in an ABA-dependent manner, whereas most of the subgroup II and III GmPYLs bind to PP2Cs in an ABA-independent manner. The subgroup III GmPYL23, which cannot interact with any of the tested PP2Cs, differs from other GmPYLs. The CL2/gate domain is crucial for GmPYLs-PP2Cs interaction, and a mutation in the conserved proline (P109S) abolishes the interaction between GmPYL1 and AtABI1. Furthermore, the ABA dependence of GmPYLs-PP2Cs interactions are partially correlated with two amino acid residues preceding the CL2/gate domain of GmPYLs. We also show that GmPYL1 interacts with AtABI1 in an ABA-dependent manner in plant cells. Three GmPYLs differentially inhibit AtABI1 and GmPP2C1 in an ABA-dependent or -enhanced manner in vitro. In addition, ectopically expressing GmPYL1 partially restores ABA sensitivity of the Arabidopsis triple mutant pyr1/pyl1/pyl4. Taken together, our results suggest that soybean GmPYLs are ABA receptors that function by interacting and inhibiting PP2Cs.
School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, P. R. China, 200240.|Shanghai Center for Plant Stress Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China, 201602.
Ge
G
Bai
Shanghai Center for Plant Stress Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China, 201602.|Institute of Plant Physiology and Ecology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China, 200032.
Da-Hai
DH
Yang
Shanghai Center for Plant Stress Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China, 201602.|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
Yang
Y
Zhao
Shanghai Center for Plant Stress Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China, 201602.|Institute of Plant Physiology and Ecology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China, 200032.
Si
S
Ha
Shanghai Center for Plant Stress Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China, 201602.
Fen
F
Yang
Shanghai Center for Plant Stress Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China, 201602.
Jun
J
Ma
Institute of Plant Physiology and Ecology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China, 200032.
Xiao-Su
XS
Gao
School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, P. R. China, 200240.
Zhi-Min
ZM
Wang
Shanghai Center for Plant Stress Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China, 201602.|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
Jian-Kang
JK
Zhu
D000040:Abscisic Acid / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D047908:Intracellular Signaling Peptides and Proteins; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism*; D000071636:Protein Phosphatase 2C; D013025:Glycine max / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D026901:Membrane Transport Proteins; C569327:PYL2 protein, Arabidopsis; D010937:Plant Growth Regulators; C540976:AT4G17870 protein, Arabidopsis; C540972:RCAR1 protein, Arabidopsis; D000040:Abscisic Acid; D010749:Phosphoprotein Phosphatases; D000071636:Protein Phosphatase 2C