Arabidopsis Duodecuple Mutant of PYL ABA Receptors Reveals PYL Repression of ABA-Independent SnRK2 Activity
Yang Zhao,
Zhengjing Zhang,
Jinghui Gao,
Pengcheng Wang,
Tao Hu,
Zegang Wang,
Yueh-Ju Hou,
Yizhen Wan,
Wenshan Liu,
Shaojun Xie,
Tianjiao Lu,
Liang Xue,
Yajie Liu,
Alberto P. Macho,
W. Andy Tao,
Ray A. Bressan,
Jian-Kang Zhu
Affiliations
Yang Zhao
Shanghai Center for Plant Stress Biology, and CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Corresponding author
Zhengjing Zhang
Shanghai Center for Plant Stress Biology, and CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
Jinghui Gao
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA; College of Animal Science and Technology, Northwest A&F University, Yangling, Shaan’xi 712100, China
Pengcheng Wang
Shanghai Center for Plant Stress Biology, and CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
Tao Hu
Shanghai Center for Plant Stress Biology, and CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Science, Wuhan 430074, Hubei, China
Zegang Wang
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
Yueh-Ju Hou
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
Yizhen Wan
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
Wenshan Liu
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
Shaojun Xie
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
Tianjiao Lu
Shanghai Center for Plant Stress Biology, and CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
Liang Xue
Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
Yajie Liu
Shanghai Center for Plant Stress Biology, and CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
Alberto P. Macho
Shanghai Center for Plant Stress Biology, and CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
W. Andy Tao
Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
Ray A. Bressan
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
Jian-Kang Zhu
Shanghai Center for Plant Stress Biology, and CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA; Corresponding author
Summary: Abscisic acid (ABA) is an important phytohormone controlling responses to abiotic stresses and is sensed by proteins from the PYR/PYL/RCAR family. To explore the genetic contribution of PYLs toward ABA-dependent and ABA-independent processes, we generated and characterized high-order Arabidopsis mutants with mutations in the PYL family. We obtained a pyl quattuordecuple mutant and found that it was severely impaired in growth and failed to produce seeds. Thus, we carried out a detailed characterization of a pyl duodecuple mutant, pyr1pyl1/2/3/4/5/7/8/9/10/11/12. The duodecuple mutant was extremely insensitive to ABA effects on seed germination, seedling growth, stomatal closure, leaf senescence, and gene expression. The activation of SnRK2 protein kinases by ABA was blocked in the duodecuple mutant, but, unexpectedly, osmotic stress activation of SnRK2s was enhanced. Our results demonstrate an important role of basal ABA signaling in growth, senescence, and abscission and reveal that PYLs antagonize ABA-independent activation of SnRK2s by osmotic stress. : Zhao et al. generated duodecuple and quattuordecuple Arabidopsis PYL ABA receptor mutants. Characterization of the mutants revealed that the ABA receptors are critical for plant growth and development and negatively regulate ABA-independent SnRK2 activity by interacting with and inhibiting osmotic stress-activated SnRK2 protein kinases. Keywords: abscisic acid, PYL, SnRK2, drought stress, osmotic stress, ABA-dependent, ABA-independent
