Figure 5.

Schematic overview of the putative roles of ERF6 and ERF11 under stress. Under basal levels of stress (plain arrows and proteins), ERF11 and ERF6 are lowly expressed. Low levels of ERF11 proteins are sufficient to repress the activation of the stress response mechanisms, as they are likely more abundant than the active, phosphorylated ERF6 proteins. Under higher stress levels (dashed arrows and proteins), ACC accumulates and MPK3/MPK6 phosphorylates and thereby activates ERF6. ERF6 now outcompetes ERF11 proteins on the promoter of the target genes, activating tolerance mechanisms and growth inhibition. However, ERF6 also transcriptionally activates ERF11, increasing ERF11 protein levels, which enables a rapid inhibition of the stress response when the stress levels decrease. P, Phosphorylation residue.