Assessing the Role of ETHYLENE RESPONSE FACTOR Transcriptional Repressors in Salicylic Acid-Mediated Suppression of Jasmonic Acid-Responsive Genes.
Salicylic acid (SA) and jasmonic acid (JA) cross-communicate in the plant immune signaling network to finely regulate induced defenses. In Arabidopsis, SA antagonizes many JA-responsive genes, partly by targeting the ETHYLENE RESPONSE FACTOR (ERF)-type transcriptional activator ORA59. Members of the ERF transcription factor family typically bind to GCC-box motifs in the promoters of JA- and ethylene-responsive genes, thereby positively or negatively regulating their expression. The GCC-box motif is sufficient for SA-mediated suppression of JA-responsive gene expression. Here, we investigated whether SA-induced ERF-type transcriptional repressors, which may compete with JA-induced ERF-type activators for binding at the GCC-box, play a role in SA/JA antagonism. We selected ERFs that are transcriptionally induced by SA and/or possess an EAR transcriptional repressor motif. Several of the 16 ERFs tested suppressed JA-dependent gene expression, as revealed by enhanced JA-induced PDF1.2 or VSP2 expression levels in the corresponding erf mutants, while others were involved in activation of these genes. However, SA could antagonize JA-induced PDF1.2 or VSP2 in all erf mutants, suggesting that the tested ERF transcriptional repressors are not required for SA/JA cross-talk. Moreover, a mutant in the co-repressor TOPLESS, that showed reduction in repression of JA signaling, still displayed SA-mediated antagonism of PDF1.2 and VSP2. Collectively, these results suggest that SA-regulated ERF transcriptional repressors are not essential for antagonism of JA-responsive gene expression by SA. We further show that de novo SA-induced protein synthesis is required for suppression of JA-induced PDF1.2, pointing to SA-stimulated production of an as yet unknown protein that suppresses JA-induced transcription.
Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, CH Utrecht, The Netherlands.
Lotte
L
Caarls
Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, CH Utrecht, The Netherlands.
Dieuwertje
D
Van der Does
Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, CH Utrecht, The Netherlands.
Richard
R
Hickman
Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, CH Utrecht, The Netherlands.
Wouter
W
Jansen
Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, CH Utrecht, The Netherlands.|Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, CH Utrecht, The Netherlands.
Marcel C Van
MC
Verk
Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, CH Utrecht, The Netherlands.
Silvia
S
Proietti
Departamento de Fisiologia Vegetal, Centro Hispano-Luso de Investigaciones Agrarias (CIALE), Facultad de Biologia, Universidad de Salamanca, Salamanca, Spain.
Oscar
O
Lorenzo
Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-CSIC, Madrid, Spain.
Roberto
R
Solano
Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, CH Utrecht, The Netherlands.
Corné M J
CM
Pieterse
Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, CH Utrecht, The Netherlands.
Saskia C M
SC
Van Wees
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003517:Cyclopentanes / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D054883:Oxylipins / Q000494:pharmacology*; D010937:Plant Growth Regulators / Q000494:pharmacology; D020156:Salicylic Acid / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; C531343:ORA59 protein, Arabidopsis; D054883:Oxylipins; D010937:Plant Growth Regulators; D014157:Transcription Factors; C011006:jasmonic acid; D020156:Salicylic Acid
Arabidopsis thaliana; ERF transcription factors; Hormone cross-talk; Jasmonic acid; Salicylic acid; TOPLESS