AP2转录因子OsERF34正向调控水稻种子休眠OA

[Objective]Weakened seed dormancy in rice leads to pre-harvest sprouting(PHS),which severely impacts grain yield and quality,making it crucial to investigate the genetic regulatory mechanisms underlying rice seed dormancy.[Method]We generated loss-of-function mutants of the AP2/ERF transcription factor OsERF34 in the Zhonghua 11(ZH11)background using CRISPR/Cas9 technology.[Result]The oserf34 mutants exhibited severe pre-harvest sprouting and significantly reduced seed dormancy.Transcriptome analysis revealed that differentially expressed genes(DEGs)between oserf34 and the wild type were significantly enriched in plant hormone signal transduction,ROS metabolism,and glycolytic pathways,suggesting that OsERF34 may maintain seed dormancy by regulating hormone biosynthesis/metabolism,redox homeostasis,and carbohydrate metabolism.Further investigation demonstrated that the oserf34 mutant seeds showed substantially increased levels of auxin(IAA),gibberellins(GA19/GA20),and salicylic acid(SA),along with decreased proline content and elevated hydrogen peroxide(H₂O₂)and superoxide anion level.Meanwhile,the activities of antioxidant enzymes(SOD,POD,CAT)were upregulated.Additionally,the mutant endosperm exhibited significantly elevated soluble sugar content and α-amylase activity,providing an energy foundation for dormancy release.This study demonstrates that OsERF34 positively regulates rice seed dormancy through its involvement in hormone biosynthesis/metabolism,redox homeostasis regulation,and carbohydrate metabolism.[Conclusion]These findings provide novel theoretical insights and genetic resources for deciphering the molecular mechanisms of seed dormancy and germination,as well as for developing PHS-resistant rice varieties.