Nutritional strategies of haustorial and nonhaustorial oomycete plant pathogens on Solanaceous hosts revealed by RNA-seq, metabolomics, fluorescent protein tagging, and gene silencing
H. JUDELSON (1), M. Kagda (1), M. Abrahamian (1), A. Ah Fong (1) (1) University of California, U.S.A.

The ability of pathogens to acquire and utilize host nutrients is a central feature of host-microbe interactions. An analysis of genes encoding metabolic enzymes and transporters from the potato late blight pathogen, Phytophthora infestans, indicates that the pathogen is largely auxotrophic. Interestingly, its metabolism uses an amalgam of genes obtained by normal evolutionary descent and horizontal transfer. RNA and metabolite profiling during leaf and tuber infection by P. infestans identified signatures of the biotrophic and necrotrophic stages of growth, and organ-specific patterns. For example, amino acid catabolism and gluconeogenesis appear higher during tuber vs. leaf colonization, which seems to be a consequence of the higher amino acid levels of tubers. Gene silencing and subcellular localization studies using fluorescently-tagged proteins identified carbon and nitrogen assimilation genes, such as invertases and nitrate reductase, that are expressed specifically in infection structures (haustoria) and/or are essential for pathogenesis. Comparisons of oomycetes pathogenic to potato (including Phytophthora and Pythium) indicate that specialization has occurred in the pattern of expression of their metabolic enzymes during host infection, which likely reflects the adaptation of the pathogens to different lifestyles.

Abstract Number: P7-177
Session Type: Poster