摘要
Most mechanistic details of chronologically ordered regulation of leaf senescence are unknown.Regulatory networks centered on AtWRKY53 are crucial for orchestrating and integrating various senescence-related signals.Notably,AtWRKY53binds to its own promoter and represses transcription of AtWRKY53,but the biological significance and mechanism underlying this selfrepression remain unclear.In this study,we identified the VQ motif-containing protein AtVQ25as a cooperator of AtWRKY53.The expression level of AtVQ25 peaked at mature stage and was specifically repressed after the onset of leaf senescence.AtVQ25-overexpressing plants and atvq25 mutants displayed precocious and delayed leaf senescence,respectively.Importantly,we identified AtWRKY53 as an interacting partner of AtVQ25.We determined that interaction between AtVQ25 and AtWRKY53 prevented AtWRKY53from binding to W-box elements on the AtWRKY53promoter and thus counteracted the selfrepression of AtWRKY53.In addition,our RNA-sequencing data revealed that the AtVQ25-AtWRKY53 module is related to the salicylic acid(SA)pathway.Precocious leaf senescence and SA-induced leaf senescence in AtVQ25-overexpressing lines were inhibited by an SA pathway mutant,atsid2,and Nah G transgenic plants;AtVQ25-overexpressing/atwrky53 plants were also insensitive to SA-induced leaf senescence.Collectively,we demonstrated that AtVQ25 directly attenuates the self-repression of AtWRKY53 during the onset of leaf senescence,which is substantially helpful for understanding the timing of leaf senescence onset modulated by AtWRKY53.
基金
supported by grants from the National Natural Science Foundation of China(31970199)
the Natural Science Fund for Distinguished Young Scholars of Hebei Province(C2022205015)
the Central Government Guides Local Science and Technology Development Project(216Z2901G)
the S&T Program of Hebei(21322915D)
the Natural Science Foundation of Hebei Province(C2022205038,C2021205013,and C2023205049)。