Cold stress is one of the major abiotic stress factors affecting rice growth and development, leading to significant yield loss in the context of global climate change. Exploring natural variants that confer cold resistance and the underlying molecular mechanism responsible for this is the major strategy to breed cold-tolerant rice varieties. Here, we show that natural variations of a SIMILAR to RCD ONE (SRO) gene, OsSRO1c, confer cold tolerance in rice at both seedling and booting stages. Our in vivo and in vitro experiments demonstrated that OsSRO1c possesses intrinsic liquid–liquid phase-separation ability and recruits OsDREB2B, an AP2/ERF transcription factor that functions as a positive regulator of cold stress, into its biomolecular condensates in the nucleus, resulting in elevated transcriptional activity of OsDREB2B. We found that the OsSRO1c-OsDREB2B complex directly responds to low temperature through dynamic phase transitions and regulates key cold-response genes, including COLD1. Furthermore, we showed that introgression of an elite haplotype of OsSRO1c into a cold-susceptible indica rice could significantly increase its cold resistance. Collectively, our work reveals a novel cold-tolerance regulatory module in rice and provides promising genetic targets for molecular breeding of cold-tolerant rice varieties.

中文翻译：

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OsSRO1c-OsDREB2B 复合物经历蛋白质相变以增强水稻的耐寒性


寒冷胁迫是影响水稻生长发育的主要非生物胁迫因素之一，在全球气候变化的背景下导致严重的产量损失。探索赋予耐寒性的天然变体及其潜在的分子机制是培育耐寒水稻品种的主要策略。在这里，我们表明 SIMILAR to RCD ONE （SRO） 基因 OsSRO1c 的自然变异赋予水稻在幼苗和孕穗阶段的耐寒性。 我们的体内和 体外实验表明，OsSRO1c 具有内在的液-液相分离能力，并将 OsDREB2B（一种作为冷应激正调节因子的 AP2/ERF 转录因子）募集到其在细胞核中的生物分子凝聚物中，导致 OsDREB2B 的转录活性升高。我们发现 OsSRO1c-OsDREB2B 复合物通过动态相变直接响应低温并调节关键的冷响应基因，包括 COLD1。此外，我们发现 OsSRO1c 的精英单倍型渗入易感寒籼稻可以显着提高其抗寒性。总的来说，我们的工作揭示了水稻中一种新的耐寒调控模块，并为耐寒水稻品种的分子育种提供了有前途的遗传靶点。