GSE137895
Transcriptomic and phytohormone profiling reveal early stage molecular variations upon co-application of abscisic or gibberellic acids with Fusarium graminearum-challenge of wheat
A comparative transcriptomic analysis of the responses arising 24 hours after infection of the susceptible T. aestivum variety 'Fielder', by Fg with co-application of either abscisic acid (ABA), gibberellic acid (GA) or the ABA-signaling inhibitor AS6, compared to stand-alone treatments is reported. Relevance of transcriptomic responses were assessed by differential expression feature evaluations (DEFE), highlighting that co-applied GA elicits a relatively strong opposing influence on Fg modulated genes, while co-applied ABA elicits similar responses to Fg. Co-applied AS6 elicited an opposing effect on gene regulation compared to co-applied ABA, and based on its lack of biological effect, was instrumental in reducing the identity of genes relevant to eliciting ABA and GA effects, to a subset of genes, largely defined within four DEFE patterns. A more targeted investigation of the impact of the co-applied conditions with respect to plant phytohormone biosynthesis and signaling pathways, correlated with select phytohormone profiles, confirmed activation of the ABA and GA pathways. Further analyses highlighted a novel interaction, potentially representing cross-talk, between co-applied ABA and the brassinosteroid signaling pathway. Additional responses within the classical defense hormone pathways as well as auxin and cytokinin pathways were found to correlate with expected defense responses. Togther these results yield insight into a range of mechanisms potentially underlying the observed contributions of ABA and GA to wheat susceptibility and resistance respectively to Fg, raising novel hypotheses for consideration in the development of FHB resistant wheat lines and agronomic practices in the longer term. Overall design: In this paper, a comparative transcriptomic analysis of the responses arising 24 hours after infection of the susceptible T. aestivum variety 'Fielder', by Fg with co-application of either abscisic acid (ABA), gibberellic acid (GA) or the ABA-signaling inhibitor AS6, compared to stand-alone treatments is reported.