Transcriptome analysis of the grape-Elsinoë ampelina pathosystem reveals pathogenesis of E. ampelina associated with novel effectors and pathogenicity-related genes and defensive strategies of grapevine

Elsinoë ampelina is an ascomycetous fungus that causes grape anthracnose, a potentially devastating disease worldwide. In this study, a dual RNA-seq analysis was used to simultaneously monitor the fungal genes related to pathogenesis and grape genes related to defence during the interaction at 2, 3, 4, and 5 days post inoculation (dpi). Consistent with their potential roles in pathogenicity, genes for carbohydrate-active enzymes, secondary metabolites synthesis, pathogen-host interaction and those encoding secreted proteins are upregulated during infection. Based on Agrobacterium tumefaciens-mediated transient assays in Nicotiana benthamiana, we further showed that eight and nine candidate effectors suppressed BAX- and INF1-mediated programmed cell death, respectively. The host response was characterized by the induction multiple defense systems against E. ampelina, including synthesis of phenylpropanoids, stilbenes, and terpenoids biosynthesis, cell wall modifications, regulation by phytohormones, and expression of defense related genes. Together, these findings offer new insights into the molecular mechanisms underlying the grape-E. ampelina interaction.