title: Arabidopsis pentatricopeptide repeat protein SOAR1 plays a critical role in abscisic acid signalling.
abstract: A dominant suppressor of the ABAR overexpressor, soar1-1D, from CHLH/ABAR [coding for Mg-chelatase H subunit/putative abscisic acid (ABA) receptor (ABAR)] overexpression lines was screened to explore the mechanism of the ABAR-mediated ABA signalling. The SOAR1 gene encodes a pentatricopeptide repeat (PPR) protein which localizes to both the cytosol and nucleus. Down-regulation of SOAR1 strongly enhances, but up-regulation of SOAR1 almost completely impairs, ABA responses, revealing that SOAR1 is a critical, negative, regulator of ABA signalling. Further genetic evidence supports that SOAR1 functions downstream of ABAR and probably upstream of an ABA-responsive transcription factor ABI5. Changes in the SOAR1 expression alter expression of a subset of ABA-responsive genes including ABI5. These findings provide important information to elucidate further the functional mechanism of PPR proteins and the complicated ABA signalling network.
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Mei
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Shang-Chuan
authors.initials: SC
authors.lastname: Jiang
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Yan-Fen
authors.initials: YF
authors.lastname: Lu
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Fu-Qing
authors.initials: FQ
authors.lastname: Wu
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Yong-Tao
authors.initials: YT
authors.lastname: Yu
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Liang
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Xiu-Jing
authors.initials: XJ
authors.lastname: Feng
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Sergi
authors.initials: S
authors.lastname: Portoles Comeras
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Lu
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wu
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China zhangdp@tsinghua.edu.cn wangxf@biomed.tsinghua.edu.cn.
authors.forename: Xiao-Fang
authors.initials: XF
authors.lastname: Wang
authors.affiliation: MOE Systems Biology and Bioinformatics Laboratory, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China zhangdp@tsinghua.edu.cn wangxf@biomed.tsinghua.edu.cn.
authors.forename: Da-Peng
authors.initials: DP
authors.lastname: Zhang
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D018525:Germination / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; C538752:pentatricopeptide repeat protein, Arabidopsis; D000040:Abscisic Acid
keywords: Abscisic acid signalling; Arabidopsis thaliana; Mg-chelatase H subunit; pentatricopeptide repeat (PPR) protein; post-germination growth; seed germination.