水稻感知寒害分子机制阐明

2月26日，《细胞》杂志在线发表了中科院植物所种康研究组的一项研究。该研究组与中国水稻研究所钱前研究组等合作，发现了水稻感受低温的重要QTL基因COLD1及其人工驯化选择的单核苷酸多态性（SNP）赋予粳稻耐寒性的新机制。

研究发现，包含粳稻COLD1基因的籼稻近等基因系以及超表达该基因的粳稻材料都显著增强了耐寒性，而功能缺失突变体cold1-1或反义基因株系却对冷非常敏感。该基因编码一个G-蛋白信号调节因子，定位于细胞质膜和内质网。冷处理时，COLD1与G-蛋白互作激活钙离子通道，触发下游耐寒防御反应。

实验分析了127个不同水稻品种和野生稻中的COLD1基因序列，发现了7个SNP位点，其中粳稻特异的SNP2影响了COLD1蛋白活性而赋予粳稻耐寒性。该成果揭示了通过驯化得到的COLD1等位基因和特异SNP赋予水稻耐寒性的新机制。COLD1模块可直接用于对超级杂交稻亲本93-11和其他籼、粳稻的耐寒性改良，对基于分子设计培育水稻耐寒新品种具有重要的应用前景。

据了解，水稻起源于热带和亚热带地区，对低温胁迫非常敏感，尤其是苗期和孕穗期，这限制了其种植的地理位置。人工驯化和选择使粳稻种植延伸到年积温较低的寒区地带。（来源：中国科学报 丁佳）

COLD1 Confers Chilling Tolerance in Rice

Abstract Rice is sensitive to cold and can be grown only in certain climate zones. Human selection of japonica rice has extended its growth zone to regions with lower temperature, while the molecular basis of this adaptation remains unknown. Here, we identify the quantitative trait locus COLD1 that confers chilling tolerance in japonica rice. Overexpression of COLD1jap significantly enhances chilling tolerance, whereas rice lines with deficiency or downregulation of COLD1 jap are sensitive to cold. COLD1 encodes a regulator of G-protein signaling that localizes on plasma membrane and endoplasmic reticulum (ER). It interacts with the G-protein α subunit to activate the Ca2+ channel for sensing low temperature and to accelerate G-protein GTPase activity. We further identify that a SNP in COLD1, SNP2, originated from Chinese Oryza rufipogon, is responsible for the ability of COLDjap/ind to confer chilling tolerance, supporting the importance of COLD1 in plant adaptation.

原文链接：http://www.sciencedirect.com/science/article/pii/S0092867415001245