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.

中文翻译：

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WD40 蛋白 OsTTG1 促进花青素积累和 CBF 转录因子依赖性途径促进水稻耐寒


温度是影响水稻 （Oryza sativa L.） 产量的关键非生物因素，幼苗阶段的寒冷胁迫会抑制植物生长，甚至致命。在寒冷胁迫期间，花青素等抗氧化剂会在各种植物中积累，但其潜在机制尚不清楚。在这里，我们报道了水稻透明 TESTA GLABRA 1 （OsTTG1） 是水稻花青素生物合成的主要调节因子，在转录和蛋白质水平上对短期和长期寒冷胁迫做出反应。代谢组学和转录组学数据表明，OsTTG1 在寒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 与碱性螺旋-环-螺旋 148 （OsbHLH148） 和 Myb 相关 S3 （OsMYBS3） 形成 MYB-bHLH-WD （MBW） 复合物，该复合物激活脱水反应元件结合蛋白 1 （OsDREB1） 和 OsANS 基因的表达。总之，我们的研究结果揭示了 OsTTG1 协调花青素生物合成和彩色稻中冷响应基因表达的机制，为未来的水稻抗寒育种提供了遗传资源。