Characterization of transgenic Arabidopsis plants overexpressing GR-RBP4 under high salinity, dehydration, or cold stress

• Published in: Journal of experimental botany 2005-11, Vol.56 (421), p.3007-3016
• Main Authors: Kwak, Kyung Jin, Kim, Yeon Ok, Kang, Hunseung
• Format: Article
• Language: English
• Subjects: Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Biological and medical sciences; cold stress; Cold Temperature; cold tolerance; Dehydration; Desiccation; desiccation (plant physiology); Enzymes; flowers; Freezing; Fundamental and applied biological sciences. Psychology; gene expression; Gene Expression Regulation, Plant; Germination; glycine (amino acid); Glycine-rich RNA-binding protein; leaves; Metabolism; molecular sequence data; Multigene Family; Nucleic Acids - metabolism; nucleotide sequences; Plant physiology and development; Plants; Plants, Genetically Modified; Proteins; Research Papers; Reverse transcriptase polymerase chain reaction; RNA; RNA binding proteins; RNA-binding protein; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; root tips; salinity; salt stress; seed germination; Seedling growth; Sodium Chloride - pharmacology; stems; stress; transgenic Arabidopsis thaliana plants; Transgenic plants; Water - metabolism; water stress
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/eri298

A glycine-rich RNA-binding protein4 (GR-RBP4), one of the eight GR-RBP family members in Arabidopsis thaliana, was investigated for its stress-related expression, nucleic acid-binding property, and functional roles in plants subjected to various stresses including cold, high salinity, and dehydration. Real-time RT-PCR and GUS expression analyses showed that GR-RBP4 was abundantly expressed in young plants, root tips, and flowers, but weakly in mature leaves and stems, implying that GR-RBP4 is highly expressed in actively proliferating organs. The transcript level of GR-RBP4 increased markedly with cold stress, decreased significantly with salt stress, and decreased slightly with dehydration stress. In vitro nucleic acid-binding assays revealed that GR-RBP4 protein binds sequence non-specifically to RNAs and DNAs. Characterization of the transgenic Arabidopsis plants overexpressing GR-RBP4 under the control of the 35S promoter revealed that 35S::GR-RBP4 lines displayed retarded germination compared with the wild type under salt or dehydration stress. Despite the marked up-regulation of GR-RBP4 expression by cold stress, the 35S::GR-RBP4 lines did not show any noticeable changes in cold or freezing tolerance compared with wild-type plants. These results indicate that GR-RBP4 contributes differently to altered germination and seedling growth of Arabidopsis plants under various stress conditions.