Moon Seok-Jun, Min Myung Ki, Kim Jin-Ae, Kim Dool Yi, Yoon In Sun, Kwon Taek Ryun, Byun Myung Ok, Kim Beom-Gi
Gene Engineering Division, Department of Agricultural Biotechnology, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, South Korea.
Metabolic Engineering Division, Department of Agricultural Biotechnology, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, South Korea.
Front Plant Sci. 2019 Mar 28;10:297. doi: 10.3389/fpls.2019.00297. eCollection 2019.
Plants adapt to adverse environmental conditions through physiological responses, such as induction of the abscisic acid signaling pathway, stomatal regulation, and root elongation. Altered gene expression is a major molecular response to adverse environmental conditions in plants. Several transcription factors function as master switches to induce the expression of stress-tolerance genes. To find out a master regulator for the cold stress tolerance in rice, we focused on functionally identifying DREB subfamily which plays important roles in cold stress tolerance of plants. Here, we characterized (), a functionally unidentified member of the subgroup. is specifically induced under cold stress conditions among several abiotic stresses examined. This gene is dominantly expressed in leaf sheath, blade, node, and root. Transgenic rice overexpressing this gene exhibited strong cold tolerance and growth retardation, like transgenic rice overexpressing other genes. However, unlike these rice lines, transgenic rice overexpressing did not exhibit significant increases in drought or salt tolerance. Cold-responsive genes were highly induced in transgenic rice overexpressing compared to wild type. In addition, overexpression directly induced the expression of a reporter gene fused to the promoters of cold-induced genes in rice protoplasts. Therefore, OsDREB1G is a typical CBF/DREB1 transcription factor that specifically functions in the cold stress response. Therefore, could be useful for developing transgenic rice with enhanced cold-stress tolerance.
植物通过生理反应来适应不利的环境条件，例如诱导脱落酸信号通路、气孔调节和根伸长。基因表达的改变是植物对不利环境条件的主要分子反应。几种转录因子作为主开关来诱导抗逆基因的表达。为了找出水稻耐冷性的主调控因子，我们专注于功能鉴定在植物耐冷性中起重要作用的DREB亚家族。在这里，我们对该亚组中一个功能未知的成员（）进行了表征。在检测的几种非生物胁迫中，该基因在冷胁迫条件下被特异性诱导。该基因在叶鞘、叶片、节和根中大量表达。过表达该基因的转基因水稻表现出较强的耐冷性和生长迟缓，类似于过表达其他基因的转基因水稻。然而，与这些水稻品系不同的是，过表达该基因的转基因水稻在耐旱性或耐盐性方面没有显著提高。与野生型相比，过表达该基因的转基因水稻中冷响应基因被高度诱导。此外，该基因的过表达直接诱导了水稻原生质体中与冷诱导基因启动子融合的报告基因的表达。因此，OsDREB1G是一种典型的CBF/DREB1转录因子，在冷胁迫反应中具有特定功能。因此，该基因可用于培育耐冷性增强的转基因水稻。
