title: Crucial roles of the pentatricopeptide repeat protein SOAR1 in Arabidopsis response to drought, salt and cold stresses.
abstract: Whereas several mitochondrial/chloroplast pentatricopeptide repeat (PPR) proteins have been reported to regulate plant responses to abiotic stresses, no nucleus-localized PPR protein has been found to play role in these processes. In the present experiment, we provide evidence that a cytosol-nucleus dual-localized PPR protein SOAR1, functioning to negatively regulate abscisic acid (ABA) signaling in seed germination and postgermination growth, is a crucial, positive regulator of plant response to abiotic stresses. Downregulation of SOAR1 expression reduces, but upregulation of SOAR1 expression enhances, ABA sensitivity in ABA-induced promotion of stomatal closure and inhibition of stomatal opening, and plant tolerance to multiple, major abiotic stresses including drought, high salinity and low temperature. Interestingly and importantly, the SOAR1-overexpression lines display strong abilities to tolerate drought, salt and cold stresses, with surprisingly high resistance to salt stress in germination and postgermination growth of seeds that are able to potentially germinate in seawater, while no negative effect on plant growth and development was observed. So, the SOAR1 gene is likely useful for improvement of crops by transgenic manipulation to enhance crop productivity in stressful conditions. Further experimental data suggest that SOAR1 likely regulates plant stress responses at least partly by integrating ABA-dependent and independent signaling pathways, which is different from the ABI2/ABI1 type 2C protein phosphatase-mediated ABA signaling. These findings help to understand highly complicated stress and 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: Shang-Chuan
authors.initials: SC
authors.lastname: Jiang
authors.forename: Chao
authors.initials: C
authors.lastname: Mei
authors.forename: Shan
authors.initials: S
authors.lastname: Liang
authors.forename: Yong-Tao
authors.initials: YT
authors.lastname: Yu
authors.forename: Kai
authors.initials: K
authors.lastname: Lu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wu
authors.forename: Xiao-Fang
authors.initials: XF
authors.lastname: Wang
authors.forename: Da-Peng
authors.initials: DP
authors.lastname: Zhang
mesh_terms: D000040:Abscisic Acid / Q000502:physiology; D000064:Acclimatization / Q000235:genetics / Q000502:physiology; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000502:physiology*; D003080:Cold Temperature / Q000009:adverse effects; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018525:Germination / Q000235:genetics / Q000502:physiology; D009997:Osmotic Pressure; D010937:Plant Growth Regulators / Q000502:physiology; D030821:Plants, Genetically Modified; D060888:Real-Time Polymerase Chain Reaction; D054712:Salinity; D015398:Signal Transduction; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; C538752:pentatricopeptide repeat protein, Arabidopsis; D000040:Abscisic Acid