背景回顾：Rice (Oryza sativa) is sensitive to low temperatures, which affects the yield and quality of rice. Therefore, uncovering the molecular mechanisms behind chilling tolerance is a critical task for improving cold tolerance in rice cultivars. 

主要发现：Here, we report that OsWRKY63, a WRKY transcription factor with an unknown function, negatively regulates chilling tolerance in rice.  

结果1-OsWRKY63过表达和敲除表型：OsWRKY63-overexpressing lines rendered rice more sensitive to cold stress. Conversely, using a CRISPR/Cas9 genome editing approach, OsWRKY63-knockout mutants led to increased chilling tolerance.  

结果2-OsWRKY63表达模式：OsWRKY63 was expressed in all rice tissues and was induced under cold stress, dehydration stress, high salinity stress, and ABA treatment.  

结果3-OsWRKY63抑制低温相关基因：OsWRKY63 localized in the nucleus plays a role as a transcription repressor and downregulates many cold stress-related genes and reactive oxygen species scavenging-related genes. 

结果4-OsWRKY63-OsWRKY76：Molecular, biochemical, and genetic assays showed that OsWRKY76 is a direct target gene of OsWRKY63 and that its expression was suppressed by OsWRKY63. OsWRKY76-knockout lines had dramatically decreased cold tolerance, and they repressed the cold-induced expression of five OsDREB1 genes. 

结果5-OsWRKY76-OsbHLH148：OsWRKY76 interacted with OsbHLH148, transactivating the expression of OsDREB1B to enhance chilling tolerance in rice.

结论：Thus, our study suggests that OsWRKY63 negatively regulates chilling tolerance in a model of the OsWRKY63–OsWRKY76–OsDREB1B transcriptional regulatory cascade in rice. 

 摘 要 

水稻是一种对低温十分敏感的作物，这也影响了水稻的产量和质量。因此，揭示低温耐受性的分子机制对于水稻栽培种抗低温的改良育种意义重大。本文中，作者发现WRKY转录因子家族成员OsWRKY63负调控水稻的低温耐受性。OsWRKY63过表达株系表现出对低温胁迫更加敏感的表型。相反，利用CRISPR/Cas9基因组编辑技术敲除OsWRKY63基因会导致低温耐受性增强。OsWRKY63基因在所有的水稻组织中表达，并且受到低温、脱水、高盐胁迫及ABA处理的诱导表达。OsWRKY63定位于细胞核，作为转录抑制子下调许多低温胁迫相关的基因和活性氧清除相关的基因。分子、生化和遗传实验显示，OsWRKY76基因是OsWRKY63的直接靶基因，OsWRKY76基因的表达受到OsWRKY63的抑制。OsWRKY76敲除株系导致低温耐受性显著降低，并且抑制5个OsDREB1基因低温诱导表达。OsWRKY76与OsbHLH148互作，激活OsDREB1B基因的表达以增强水稻的低温耐受性。因此，本文的研究结果揭示了OsWRKY63通过OsWRKY63–OsWRKY76–OsDREB1B转录调控级联负调控水稻的低温耐受性。

 都兴林 

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