AtERF4 and AtERF7 are involved in the abscisic acid signaling response in Arabidopsis

ERFs (ethylene-responsive element binding factors) belong to a large family of transcription factors that are found exclusively in plants. A small subfamily of ERF proteins can act as transcriptional repressors. The Arabidopsis genome contains eight ERF repressors, namely AtERF3, AtERF4, AtERF7, AtERF8, AtERF9, AtERF10, AtERF11, and AtERF12. The different ERF repressors show differential expression, suggesting that they may have different function. The expression of AtERF4 can be induced by ethylene, jasmonic acid, or abscisic acid. AtERF7 can be induced by abscisic acid only. Using a transient expression system, we demonstrated that AtERF4 and AtERF7 can function as transcriptional repressors.; We found that there are 867 genes containing a GCC-box within 1000 by upstream of their start codons. Of these genes, 656 are represented in the ATH1 Arabidopsis GeneChip from Affymetrix and can be classified into five major classes: metabolism, defense and stress response, signal transduction, transcription, and cellular organization. About 18% of these genes have been classified into the defense and stress category. In addition to their roles in defense and stress responses, our analysis indicated that the GCC-box containing genes may also be involved other cellular processes. (Abstract shortened by UMI.)...