Leaf senescence, as a postmitotic senescence program, occurs not only with aging, but also in stressed or detached leaves. Although remarkable advances have been made in the last decade in understanding the mechanisms of jasmonic acid（JA）signal transduction in model plants such as Arabidopsis, the specific mechanisms by which JA induces leaf senescence are not well understood. Moreover, few studies have focused on the crosstalk between the different hormones mediating senescence. However, the molecular details of this phytohormone interaction also remain largely unknown.
Prof. YU Diqiu and his team of Xishuangbanna Tropical Botanical Garden (XTBG) found that WRKY57 functioned as a negative regulator in JA-induced leaf senescence in Arabidopsis. Further investigation indicated that WRKY57 directly repressed the expression of SENESCENCE4 (SEN4) and SENESCENCEASSOCIATED GENE12 (SAG12). Moreover, JAZ and auxin/indole-
3-acetic acid (IAA) proteins competitively interacted with the zinc-finger domain of WRKY57, which accounted for the antagonism of auxin in JA-induced leaf senescence.
A great deal of indirect evidence has confirmed that plant WRKY proteins are involved in plant senescence, but information about the biological roles of specific WRKY proteins in JA-induced senescence is limited. In their study, they revealed that auxin could antagonize JA-induced leaf senescence and that WRKY57 was a key modulator mediating the crosstalk between JA and auxin in JA-induced leaf senescence.
Because WRKYs have been suggested to integrate various hormonal and environmental signals in plants, their study provided a mechanistic understanding of how the crosstalk between the JA and auxin signaling pathways in JA-induced leaf senescence was fine-tuned by WRKY57.