Fig. 6: Potential mechanisms for MYC2 modulation of TOC1 occupancy at target defence gene promoters.

In uninfected plants, MYC2 is kept in an inactive state by the JAZ repressor complex. A TOC1 is recruited to the G-box (orange) by direct interaction with inactive MYC2, repressing defence gene expression. Detection of B. cinerea leads to COI1-mediated degradation of JAZ repressors. MYC2 undergoes a conformational change, releasing TOC1 and abolishing TOC1-mediated repression. B Inactive MYC2 promotes direct binding of TOC1 to the G-box. Active MYC2 displaces TOC1 from the G-box or recruits co-activators (X) which block TOC1 binding.