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Poster: Molecular & Cellular Plant-Microbe Interactions: MPMI


Molecular dissection of resistance signaling in watermelon fruit through transcriptomic approach
M. MANDAL (1), J. Ikerd (2), A. Soorni (3), C. Kousik (2) (1) ORISE Participant sponsored by the U.S. Vegetable Laboratory, USDA, ARS., U.S.A.; (2) U.S. department of Agriculture, Agricultural Research Service, U.S. Vegetable Laboratory, U.S.A.; (3) Depar

Plant defense signaling involves a complex array of events initiated by direct or indirect interactions between pathogen effectors and host resistance proteins. Our study involves developing watermelon (Citrullus lanatus) lines resistant to various pests and pathogens through conventional breeding techniques. One of the most common and widely spread diseases in watermelon is Phytophthora fruit rot caused by Phytophthora capsici, which is especially severe in the southeastern US due to prevalence of favorable weather conditions. In order to elucidate the molecular mechanism of signaling events that occur during watermelon - Phytophthora interactions we are utilizing the available watermelon and P. capsici genome sequence data along with our RNA-seq data to identify the differentially regulated transcriptome between resistant and susceptible watermelon lines. Our preliminary data indicates that most sample sequence reads matched to watermelon genome (70-90%) and the pathogen transcript reads were higher in susceptible cultivar ‘Sugar Baby’ (5-30%) when compared to resistant germplasm line ‘USVL020-PFR’ (0.5-1%). The genotypic data correlates well with the phenotypic data. The overall goal is to identify plant defense markers contributing to host resistance against P. capsici that will prove useful in watermelon breeding programs.