ARS | Publication request: Selection of candidate genes involved in the defense mechanisms of Phytophthora infestans against fungicides by EST analysis

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: May 15, 2012
Publication Date: June 30, 2012
Citation: Champaco, E., Larkin, R.P., De Los Reyes, B. 2012. Selection of candidate genes involved in the defense mechanisms of Phytophthora infestans against fungicides by EST analysis [abstract]. Phytopathology. 102:54.20.

Technical Abstract: Preliminary research using a functional genomics approach was conducted to gain insights on how P. infestans responds to fungicides and the possible implications of these responses on its ability to adapt to such selection pressure. Two isolates with subtle differences in mefenoxam resistance were exposed to low and moderate concentrations of mancozeb or mefenoxam. A high-titer composite primary library consisting of 1.3 x 107 near full-length cDNA clones was constructed to ensure broad representation of genes expressed by both strains under fungicide treatments. Initial low-depth sequencing of 500 cDNA clones revealed that a large proportion of transcripts represent genes with binding (47%) and catalytic activities (34%). A smaller proportion represent genes with structural (10%), transport (4%), protein serine/threonine kinase (3%) and efflux, plant pathogenesis and defense (2%) related functions. This latter category is represented by multidrug resistance, elicitin-like and crinkler family proteins known to play important roles in programmed cell death and defense. These trends suggest a potentially interesting parallel between the mechanisms of plant responses to pathogens and pathogen responses to xenobiotic chemicals, perhaps through specialized functions of evolutionarily conserved proteins. Our initial results underscore the need to investigate the potential of these candidate genes to confer a selective advantage in pathogen-fungicide interactions.