System-level transcriptomics of wheat responses to FHB identifies gene
regulatory networks and conserved master regulators as key
susceptibility genes
Abstract
Plant diseases are driven by an intricate set of defense mechanisms
counterbalanced by the expression of host susceptibility factors
promoted through the action of pathogen effectors. In spite of their
central role in the establishment of the pathology, the primary
components of plant susceptibility are still poorly understood and
challenging to trace. Focusing on Fusarium head blight (FHB) in bread
wheat and integrating plant transcriptomics responses from a susceptible
cultivar facing Fusarium graminearum strains of different
aggressiveness, we described unexpected differential expression of a
conserved set of transcription factors and an original subset of master
regulators were evidenced using a regulation network approach. The
dual-integration with the expression data of pathogen effector genes
combined with database mining, demonstrated robust connections with the
plant molecular regulators and identified relevant candidate genes
involved in plant immunity, mostly able to suppress plant defense
mechanisms. Furthermore, taking advantage of wheat cultivars of
contrasting susceptibility levels, a refined list of 142 conserved
susceptibility gene candidates were proposed to be necessary host’s
determinants for the establishment of a compatible interaction. In this
respect, our findings provide new clues for improving FHB control in
wheat and also could conceivably leverage further original researches
dealing with a broader spectrum of plant pathogens.