A targeted proteomic approach to identify protein markers for Didymella pinodes resistance in pea

Abstract

Ascochyta blight, caused by Didymella pinodes, is one of major diseases of pea worldwide. Only low levels of resistance are available in pea cultivars. Quantitative Trait Loci associated with resistance to this disease have been identified, but the resistant genes underlying these QTLs are unknown what limits their practical application in Marker Assisted Selection. These QTLs are currently being saturated with additional markers and candidate gene identification is in progress what will certainly improve their use in MAS. In a further attempt to exploit other types of markers we identified protein markers and explored the feasibility for their use in selection breeding. Shotgun proteomic experiments revealed several stress-related proteins differentially expressed in resistant reactions to D. pinodes in pea, 35 of them matching with previous Microarray and SAGE gene expression analysis. By using a targeted proteomic strateg y these proteins were searched and measured at constitutive level in a RIL population segregating for resistance. Results still in progress, suggest that at least 18 of these proteins are mostly represented only in the resistant lines and could be used as markers for resistance. Applicability of this strategy in MAS will be presented and discussed.