Zhu Chenli, Yang Xinghai, Chen Weiwei, Xia Xiuzhong, Zhang Zhongqiong, Qing Dongjin, Nong Baoxuan, Li Jingcheng, Liang Shuhui, Luo Shuangshuang, Zhou Weiyong, Yan Yong, Dai Gaoxing, Li Danting, Deng Guofu
Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China.
College of Agriculture, Guangxi University, Nanning 530004, China.
Plant Physiol. 2024 Dec 23;197(1). doi: 10.1093/plphys/kiae604.
Temperature is a critical abiotic factor affecting rice (Oryza sativa L.) yields, and cold stress at the seedling stage can inhibit plant growth or even be fatal. Antioxidants such as anthocyanins accumulate in a variety of plants during cold stress, but the underlying mechanisms are not well understood. Here, we report that rice TRANSPARENT TESTA GLABRA 1 (OsTTG1), a major regulator of anthocyanin biosynthesis in rice, responds to short- and long-term cold stress at both the transcriptional and protein levels. Metabolomic and transcriptomic data indicate that OsTTG1 activates the expression of anthocyanidin synthase (OsANS) genes under cold stress. Our data also suggest that OsTTG1 forms a MYB-bHLH-WD (MBW) complex with Basic helix-loop-helix 148 (OsbHLH148) and Myb-related S3 (OsMYBS3), and this complex activates the expression of Dehydration-responsive element-binding protein 1 (OsDREB1) and OsANS genes. Together, our findings reveal the mechanisms by which OsTTG1 coordinates both anthocyanin biosynthesis and the expression of cold-responsive genes in colored rice, providing genetic resources for future cold resistance breeding in rice.
温度是影响水稻（Oryza sativa L.）产量的关键非生物因素，苗期的冷胁迫会抑制植株生长甚至导致死亡。花青素等抗氧化剂在多种植物遭受冷胁迫时会积累，但其潜在机制尚不清楚。在此，我们报道水稻花青素生物合成的主要调节因子透明种皮光滑1（OsTTG1）在转录和蛋白质水平上对短期和长期冷胁迫均有响应。代谢组学和转录组学数据表明，OsTTG1在冷胁迫下激活花青素合酶（OsANS）基因的表达。我们的数据还表明，OsTTG1与基本螺旋-环-螺旋148（OsbHLH148）和Myb相关蛋白S3（OsMYBS3）形成MYB-bHLH-WD（MBW）复合体，该复合体激活脱水响应元件结合蛋白1（OsDREB1）和OsANS基因的表达。总之，我们的研究结果揭示了OsTTG1在有色水稻中协调花青素生物合成和冷响应基因表达的机制，为未来水稻抗寒育种提供了遗传资源。
