Glycine-rich RNA-binding protein 7 affects abiotic stress responses by regulating stomata opening and closing in Arabidopsis thaliana.
Despite the fact that glycine-rich RNA-binding proteins (GRPs) have been implicated in the responses of plants to environmental stresses, their physiological functions and mechanisms of action in stress responses remain largely unknown. Here, we assessed the functional roles of GRP7, one of the eight GRP family members in Arabidopsis thaliana, on seed germination, seedling growth, and stress tolerance under high salinity, drought, or cold stress conditions. The transgenic Arabidopsis plants overexpressing GRP7 under the control of the cauliflower mosaic virus 35S promoter displayed retarded germination and poorer seedling growth compared with the wild-type plants and T-DNA insertional mutant lines under high salinity or dehydration stress conditions. By contrast, GRP7 overexpression conferred freezing tolerance in Arabidopsis plants. GRP7 is expressed abundantly in the guard cells, and has been shown to influence the opening and closing of the stomata, in accordance with the prevailing stress conditions. GRP7 is localized to both the nucleus and the cytoplasm, and is involved in the export of mRNAs from the nucleus to the cytoplasm under cold stress conditions. Collectively, these results provide compelling evidence that GRP7 affects the growth and stress tolerance of Arabidopsis plants under high salt and dehydration stress conditions, and also confers freezing tolerance, particularly via the regulation of stomatal opening and closing in the guard cells.
Kim
Jin Sun
JS
Department of Plant Biotechnology, Agricultural Plant Stress Research Center and Biotechnology Research Institute, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea.
Jung
Hyun Ju
HJ
Lee
Hwa Jung
HJ
Kim
Kyung Ae
KA
Goh
Chang-Hyo
CH
Woo
Youngmin
Y
Oh
Seung Han
SH
Han
Yeon Soo
YS
Kang
Hunseung
H
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism; D003593:Cytoplasm / Q000737:chemistry / Q000378:metabolism; D005615:Freezing; D018525:Germination / Q000235:genetics; D016254:Mutagenesis, Insertional; D054046:Plant Stomata / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000502:physiology; D011061:Poly A / Q000378:metabolism; D034443:RNA Transport / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism; D014867:Water / Q000378:metabolism
D029681:Arabidopsis Proteins; D011061:Poly A; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012965:Sodium Chloride; D014867:Water; C118496:GRP7 protein, Arabidopsis