Expression data in WT and erf6 mutant under high-light treatment

Reactive oxygen species (ROS) have been characterized as both important signaling molecules and universal stressors that mediate many developmental and physiological responses. So far, details of the transcriptional mechanism of ROS-responsive genes are still largely unknown. In the study reported herein, we identified eight potential ROS-responsive cis-acting elements (ROSEs) from the promoters of genes upregulated by ROS. We also found that the APETALA2 (AP2/EREBP)-type transcription factor ERF6 could bind specifically to the ROSE7/GCC box. Co-expression of ERF6 enhanced luciferase activity driven by ROSE7. ERF6 interacted physically with mitogen-activated protein kinase 6 (MPK6), and also served as a substrate of MPK6. MPK6-mediated ERF6 phosphorylation at both Ser 266 and Ser 269 affected the dynamic alternation of ERF6 protein, which resulted in changes in ROS-responsive gene transcription. These data might provide new insight into the mechanisms that regulate ROS-responsive gene transcription via a complex of MPK6, ERF6, and the ROSE7/GCC box.

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