Cold‐inducible zinc finger‐containing glycine‐rich RNA‐binding protein contributes to the enhancement of freezing tolerance in Arabidopsis thaliana

作者：Yeon‐Ok Kim, Jin Sun Kim, Hunseung Kang · 发表于：The Plant Journal · 年份：2005 · DOI：10.1111/j.1365-313x.2005.02420.x · 被引用次数：212 · 研究领域：Plant Molecular Biology Research、RNA Research and Splicing、Plant Stress Responses and Tolerance

Glycine-rich RNA-binding proteins (GR-RBPs) have been implicated to play roles in post-transcriptional regulation of gene expression in plants under various stress conditions, but the functional roles of GR-RBPs under stress conditions remain to be verified. Here, we examine the biological roles of a GR-RBP, designated atRZ-1a, in Arabidopsis thaliana under stress conditions. atRZ-1a was expressed ubiquitously in various Arabidopsis organs including stems, roots, leaves, flowers, and siliques. The transcript level of atRZ-1a increased markedly by cold stress, whereas its expression was marginally downregulated by drought stress or abscisic acid treatment. Germination and seedling growth of the loss-of-function mutants were retarded remarkably compared with those of the wild type under cold stress. In contrast, the transgenic Arabidopsis plants that overexpress atRZ-1a displayed earlier germination and better seedling growth than the wild type under cold stress. Moreover, the atRZ-1a-overexpressing transgenic Arabidopsis plants were more freezing tolerant than the wild-type plants. Heterologous expression of atRZ-1a in Escherichia coli demonstrated that the E. coli cells expressing atRZ-1a displayed much higher growth rate than the non-transformed cells after cold shock. These results provide evidence that atRZ-1a affects seed germination and seedling growth under low temperature and plays a role in the enhancement of freezing tolerance in Arabidopsis plants.