Arabidopsis WRKY28 transcription factor is required for resistance to necrotrophic pathogen, Botrytis cinerea

Abstract

Arabidopsis thaliana WRKY28, which is strongly induced by H2O2 stress, is one of the group II WRKY proteins and responds to Botrytis cinerea. In this study, we successfully generated up and down-regulating WRKY28 transgenic A. thaliana lines. Our investigationinto the action of WRKY28 demonstrated that the down-regulation of WRKY28 resulted in susceptible of plants. The enhanced susceptible in down-regulating plants was associated with the suppression of jasmonate (JA) and ethylene (ET) regulated PDF1.2gene by the necrotrophic fungal pathogen B. cinerea. In contrast, disease resistance and the expressions of JA and ET regulated PDF1.2 genes are slightly enhanced in WRKY28 over-expressing plants. Thus, pathogen-induced WRKY28 transcription factor plays a key role in JA and ET mediated defense responses to B. cinerea. These results provide a genetic evidence of WRKY28 in plant defense.   Key words: Transcription factor, Botrytis cinerea, necrotroph fungus.