TY - JOUR TI - Negative regulation of ABA signaling by WRKY33 is critical for Arabidopsis immunity towards Botrytis cinerea 2100 AU - Liu, Shouan AU - Kracher, Barbara AU - Ziegler, Jörg AU - Birkenbihl, Rainer P AU - Somssich, Imre E A2 - Greenberg, Jean T VL - 4 PY - 2015 DA - 2015/06/15 SP - e07295 C1 - eLife 2015;4:e07295 DO - 10.7554/eLife.07295 UR - https://doi.org/10.7554/eLife.07295 AB - The Arabidopsis mutant wrky33 is highly susceptible to Botrytis cinerea. We identified >1680 Botrytis-induced WRKY33 binding sites associated with 1576 Arabidopsis genes. Transcriptional profiling defined 318 functional direct target genes at 14 hr post inoculation. Comparative analyses revealed that WRKY33 possesses dual functionality acting either as a repressor or as an activator in a promoter-context dependent manner. We confirmed known WRKY33 targets involved in hormone signaling and phytoalexin biosynthesis, but also uncovered a novel negative role of abscisic acid (ABA) in resistance towards B. cinerea 2100. The ABA biosynthesis genes NCED3 and NCED5 were identified as direct targets required for WRKY33-mediated resistance. Loss-of-WRKY33 function resulted in elevated ABA levels and genetic studies confirmed that WRKY33 acts upstream of NCED3/NCED5 to negatively regulate ABA biosynthesis. This study provides the first detailed view of the genome-wide contribution of a specific plant transcription factor in modulating the transcriptional network associated with plant immunity. KW - global Arabidopsis WRKY33 binding siteArabidopsis WRKY33 binding sites KW - WRKY33-mediated resistance KW - ABA signaling KW - ChIP-seq KW - RNA-seq JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -