At ERF #111/ ABR 1 is a transcriptional activator involved in the wounding response

Summary At ERF #111/ ABR 1 belongs to the group X of the ERF / AP 2 transcription factor family ( GXERF s) and is shoot specifically induced under submergence and hypoxia. It was described to be an ABA ‐response repressor, but our data reveal a completely different function. Surprisingly, At ERF #111 expression is strongly responsive to wounding stress. Expression profiling of ERF #111 ‐overexpressing ( OE ) plants, which show morphological phenotypes like increased root hair length and number, strengthens the hypothesis of At ERF #111 being involved in the wounding response, thereby acting as a transcriptional activator of gene expression. Consistent with a potential function outside of oxygen signalling, we could not assign At ERF #111 as a target of the PRT 6 N‐degron pathway, even though it starts with a highly conserved N‐terminal Met−Cys ( MC ) motif. However, the protein is unstable as it is degraded in an ubiquitin‐dependent manner. Finally, direct target genes of At ERF #111 were identified by microarray analyses and subsequently confirmed by protoplast transactivation assays. The special roles of diverse members of the plant‐specific GXERF s in coordinating stress signalling and wound repair mechanisms have been recently hypothesized, and our data suggest that At ERF #111 is indeed involved in these processes.