Fig. 5.

Working model of the role of JAZ7 in dark-induced leaf senescence.

Under darkness, expression of the JAZ7 gene is significantly induced, and the jaz7 mutant had enhanced dark-induced leaf senescence. JAZ7-mediated dark-induced senescence might be COI1 dependent and antagonistic to regulation by MYCs. During darkness, the mutation of JAZ7 might partially liberate MYCs from suppression, leading the MYCs to bind to the G-box/G-box-like motifs in the promoters and resulting in the up-regulation of the downstream genes related to indole-GS biosynthesis, sulphate metabolism, callose deposition, and JA-mediated signalling pathways.