Transcription Factor Negatively Regulates Leaf Senescence in .

Leaf senescence is the final stage of leaf development and is essential for storage properties and crop productivity. WRKY transcription factors have been revealed to play crucial roles in several biological processes during plant growth and development, especially in leaf senescence. However, the functions of WRKY transcription factors in leaf senescence remain unclear. In the present study, , one paralogue of , was cloned from the cultivar "Zhongshuang11 (ZS11)". We found that Bna.A07.WRKY70 contains a highly conserved WRKY domain and is most closely related to WRKY70. The subcellular localization and transcriptional self-activation assays indicated that Bna.A07.WRKY70 functions as a transcription factor. Meanwhile, RT-qPCR and promoter-GUS analysis showed that is predominantly expressed in the leaves of and rosette leaves of . In addition, our results demonstrated that ectopic expression of in mutants could restore the senescence phenotypes to wild-type levels. Consistently, the expression levels of three senescence-related marker genes of mutants were restored to wild-type levels by ectopic expression of . These findings improve our understanding of the function of in and provide a novel strategy for breeding the new stay-green cultivars in rapeseed through genetic manipulation.