Role of an Arabidopsis AP2/EREBP-Type Transcriptional Repressor in Abscisic Acid and Drought Stress Responses

Abstract

The phytohormone abscisic acid (ABA) modulates the expression of many genes important to plant growth and development and to stress adaptation. In this study, we found that an APETALA2/EREBP-type transcription factor, AtERF7, plays an important role in ABA responses. AtERF7 interacts with the protein kinase PKS3, which has been shown to be a global regulator of ABA responses. AtERF7 binds to the GCC box and acts as a repressor of gene transcription. AtERF7 interacts with the Arabidopsis thaliana homolog of a human global corepressor of transcription, AtSin3, which in turn may interact with HDA19, a histone deacetylase. The transcriptional repression activity of AtERF7 is enhanced by HDA19 and AtSin3. Arabidopsis plants overexpressing AtERF7 show reduced sensitivity of guard cells to ABA and increased transpirational water loss. By contrast, AtERF7 and AtSin3 RNA interference lines show increased sensitivity to ABA during germination. Together, our results suggest that AtERF7 plays an important role in ABA responses and may be part of a transcriptional repressor complex and be regulated by PKS3.

Arabidopsis histone deacetylase 6: a green link to RNA silencing

“…Furthermore, AtHDA19 antagonizes the histone acetyltransferase AtGCN5 in regulating the maintenance of embryo axis formation and light-responsive gene expression, respectively (Benhamed et al, 2006;Long et al, 2006). Besides development, AtHDA19 is required for jasmonic acid-and ethylene-mediated plant responses to plant pathogens, for responses of cultured cells to sucrose starvation and for transcriptional repression in response to abscisic acid, drought and salt stress (Song et al, 2005;Zhou et al, 2005;Nicolai et al, 2006;Song and Galbraith, 2006). The latter response is likely executed by an AtHDA19/SIN3 repressor complex that is recruited to target genes via ethyleneresponsive element binding factors (ERFs) (Song et al, 2005;Song and Galbraith, 2006).…”

“…Besides development, AtHDA19 is required for jasmonic acid-and ethylene-mediated plant responses to plant pathogens, for responses of cultured cells to sucrose starvation and for transcriptional repression in response to abscisic acid, drought and salt stress (Song et al, 2005;Zhou et al, 2005;Nicolai et al, 2006;Song and Galbraith, 2006). The latter response is likely executed by an AtHDA19/SIN3 repressor complex that is recruited to target genes via ethyleneresponsive element binding factors (ERFs) (Song et al, 2005;Song and Galbraith, 2006). In contrast to AtHDA19, the role of AtHDA6 in development appears to be minor, since Athda6 mutants develop normally under standard growth conditions with the exception of slightly late flowering (Probst et al, 2004).…”

The Hevea brasiliensis AP2/ERF superfamily: from ethylene signalling to latex harvesting and physiological disease response

“…For instance, the ERF4 and ERF7 genes play an important role in the response to ABA (Yang et al, 2005;Song et al, 2005). The overexpression of ERF7 increased the sensitivity to ABA in guard cells (Song et al, 2005). The suppression of ERF-VIII also requires interactions with other transcription factors.…”

“…However, these genes showed differential expression and distinct roles in plant growth and development as well as in response to environmental stress. For instance, the ERF4 and ERF7 genes play an important role in the response to ABA (Yang et al, 2005;Song et al, 2005). The overexpression of ERF7 increased the sensitivity to ABA in guard cells (Song et al, 2005).…”

Enhancement of Abscisic Acid Sensitivity and Reduction of Water Consumption in Arabidopsis by Combined Inactivation of the Protein Phosphatases Type 2C ABI1 and HAB1

“…The TFs comprise ABA-responsive element (ABRE)-binding proteins (ABA-INSENSITIVE5 [ABI5]/ABF/AREB/ AtbZIP family), ABI3/VP1/B3, ABI4/APETALA2, MYC, MYB, and HD-ZIP domain proteins (Giraudat et al, 1992;Suzuki et al, 1997;Finkelstein et al, 1998;Choi et al, 2000;Finkelstein and Lynch, 2000;Uno et al, 2000;Bensmihen et al, 2002;Himmelbach et al, 2002;Abe et al, 2003). Most of these TFs play a positive role in ABA signaling, but some of them function as repressors of ABA response (Himmelbach et al, 2002;Pandey et al, 2005;Song et al, 2005).…”