Cold tolerance at the booting (CTB) stage is a major factor limiting rice (Oryza sativa L.) productivity and geographical distribution. A few cold-tolerance genes have been identified, but they either need to be overexpressed to result in CTB or cause yield penalties, limiting their utility for breeding. Here, we characterize the function of the cold-induced transcription factor WRKY53 in rice. The wrky53 mutant displays increased CTB, as determined by higher seed setting. Low temperature is associated with lower gibberellin (GA) contents in anthers in the wild type but not in the wrky53 mutant, which accumulates slightly more GA in its anthers. WRKY53 directly binds to the promoters of GA biosynthesis genes and transcriptionally represses them in anthers. In addition, we uncover a possible mechanism by which GA regulates male fertility: SLENDER RICE1 (SLR1) interacts with and sequesters two critical transcription factors for tapetum development, UNDEVELOPED TAPETUM1 (UDT1), and TAPETUM DEGENERATION RETARDATION (TDR), and GA alleviates the sequestration by SLR1, thus allowing UDT1 and TDR to activate transcription. Finally, knocking out WRKY53 in diverse varieties increases cold tolerance without a yield penalty, leading to a higher yield in rice subjected to cold stress. Together, these findings provide a target for improving CTB in rice.

中文翻译：

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WRKY53通过微调花药赤霉素水平来负调控水稻孕穗期的耐寒性。


孕穗期（CTB）的耐寒性是限制水稻（Oryza sativa L.）生产力和地理分布的主要因素。一些耐寒基因已被鉴定，但它们要么需要过度表达才能导致 CTB，要么导致产量下降，从而限制了它们的育种用途。在这里，我们表征了水稻中冷诱导转录因子 WRKY53 的功能。 wrky53 突变体表现出增加的 CTB，这由较高的结籽率决定。低温与野生型花药中较低的赤霉素 (GA) 含量有关，但与 wrky53 突变体无关，该突变体在其花药中积累了稍多的 GA。 WRKY53 直接与 GA 生物合成基因的启动子结合，并在花药中转录抑制它们。此外，我们发现了 GA 调节男性生育能力的可能机制：SLENDER RICE1 (SLR1) 与绒毡层发育的两个关键转录因子 UNDEVELOPED TAPETUM1 (UDT1) 和 TAPETUM DEGENERATION RETARDATION (TDR) 相互作用并隔离，并且 GA 减轻了被 SLR1 隔离，从而允许 UDT1 和 TDR 激活转录。最后，在不同品种中敲除WRKY53可以提高耐冷性，而不会影响产量，从而使遭受冷胁迫的水稻产量更高。总之，这些发现为改善水稻的 CTB 提供了目标。