杨博等《Journal of Biological Chemistry》2023年

论文题目：The Abscisic Acid-Responsive Element Binding Factors (ABFs)-MAPKKK18 moduleregulates ABA- induced leaf senescence in Arabidopsis.

论文作者：Guoying Zhao#, Qian Cheng#, Yuting Zhao, Feifei Wu, Bangbang Mu, Jiping Gao,Liu Yang, Jingli Yan, Hanfeng Zhang, Xing Cui, Qinqin Chen, Fangxiao Lu,Qianqian Ao, Asma Amdouni, Yuan-Qing Jiang*, Bo Yang*.

论文摘要：The Mitogen-Activated Protein Kinase Kinase Kinase 18 (MAPKKK18) has been reported to play a role in abiotic stress priming in long-term abscisic acid (ABA) response including drought tolerance and leaf senescence. However, the upstream transcriptional regulators of MAPKKK18 remain to be determined. Here, we report ABA-Responsive Element (ABRE) Binding Factors (ABFs) as upstream transcriptionfactors(TFs) of MAPKKK18 expression.Mutants of abf2, abf3, abf4 and abf2abf3abf4 dramatically reduced the transcription of MAPKKK18. Our electrophoresis mobility shift assay (EMSA)and dual-luciferase reporter assay demonstrated that ABF2, ABF3, and ABF4 bound to ABREcis-elements within the promoter of MAPKKK18to transactivate its expression. Furthermore, enrichments of the promoter region of MAPKKK18 by ABF2, ABF3, and ABF4 were confirmed by in vivochromatin immunoprecipitation coupled with qPCR(ChIP-qPCR). Additionally, we found that mutants of mapkkk18 exhibited obvious delayed leaf senescence. Moreover, a genetic study showed that overexpression of ABF2, ABF3, and ABF4 in the background of mapkkk18 mostly phenocopied the stay-green phenotype of mapkkk18 and, expression levels of five target genes of ABFs, that is, NYE1, NYE2, NYC1, PAO, and SAG29 were attenuated as a result of MAPKKK18 mutation. These findings demonstrate that ABF2, ABF3, and ABF4 act as transcription regulators of MAPKKK18, and also suggest that, at least in part,ABA acts in primingleaf senescence via ABF-induced expression of MAPKKK18.

论文链接：https://www.jbc.org/article/S0021-9258(23)00192-8/fulltext