title: SRK2C, a SNF1-related protein kinase 2, improves drought tolerance by controlling stress-responsive gene expression in Arabidopsis thaliana.
abstract: Protein phosphorylation/dephosphorylation are major signaling events induced by osmotic stress in higher plants. Here, we showed that a SNF1-related protein kinase 2 (SnRK2), SRK2C, is an osmotic-stress-activated protein kinase in Arabidopsis thaliana that can significantly impact drought tolerance of Arabidopsis plants. Knockout mutants of SRK2C exhibited drought hypersensitivity in their roots, suggesting that SRK2C is a positive regulator of drought tolerance in Arabidopsis roots. Additionally, transgenic plants with CaMV35S promoter::SRK2C-GFP displayed higher overall drought tolerance than control plants. Whereas stomatal regulation in 35S::SRK2C-GFP plants was not altered, microarray analysis revealed that their drought tolerance coincided with up-regulation of many stress-responsive genes, for example, RD29A, COR15A, and DREB1A/CBF3. From these results, we concluded that SRK2C is capable of mediating signals initiated during drought stress, resulting in appropriate gene expression. Our present study reveals new insights around signal output from osmotic-stress-activated SnRK2 protein kinase as well as supporting feasibility of manipulating SnRK2 toward improving plant osmotic-stress tolerance.
authors.affiliation: Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, 3-1-1 Kouyadai, Tsukuba 305-0074, Japan.
authors.forename: Taishi
authors.initials: T
authors.lastname: Umezawa
authors.forename: Riichiro
authors.initials: R
authors.lastname: Yoshida
authors.forename: Kyonoshin
authors.initials: K
authors.lastname: Maruyama
authors.forename: Kazuko
authors.initials: K
authors.lastname: Yamaguchi-Shinozaki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shinozaki
mesh_terms: D000064:Acclimatization; D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D004190:Disasters; D005786:Gene Expression Regulation; D009997:Osmotic Pressure; D018517:Plant Roots / Q000502:physiology; D030821:Plants, Genetically Modified; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; C116166:COR15 protein, Arabidopsis; C114578:DREB1A protein, Arabidopsis; C492978:SnRK2 protein, Arabidopsis; D014157:Transcription Factors; D017346:Protein Serine-Threonine Kinases