Tuber apoplastic hydrophobic proteins differentially expressed in

M. B. FERNANDEZ (1), M. G. GUEVARA (1), G. R. DALEO (1), M. R. PAGANO

Oregon, EEUU

Congreso; Annual Meeting of Phytopathological Society (APS); 2009

During plant pathogen interaction, oomycetes secrete effectors into the plant apoplast where they interact with host resistance proteins, which are accumulated after wounding or infection. Expression profile of pathogenesis related proteins is proportional to the resistance of different cultivars towards P. infestans infection. The aim of this work was to analyse the pattern of expression of apoplastic hydrophobic proteins (AHPs), after wounding or infection, in tubers from two potato cultivars with different resistance to P. infestans. Intercellular fluid was extracted from tubers (IFT) and chromatographed into a PepRPC™ HR5-5 column in FPLC eluted with a linear gradient of 75% acetonitrile. Then, AHPs were analyzed by SDS-PAGE and identified by MALDI TOF. Results obtained shown that in the resistant cultivar (Innovator), the AHPs concentration was higher than in the susceptible cultivar (Spunta), in all times and conditions assayed. Quantitative and qualitative changes were observed in hydrophobic proteins in both cultivars after infection. In Spunta cultivar patatin precursors and a protein of 9 KDa were induced after infection. In Innovator cultivar, the levels of protease inhibitors, patatin precursors and a protein of 16 KDa were increased. The results obtained here suggest that changes in the AHPs levels could be necessary to protect the plant against pathogens. Furthermore, those basal levels of AHPs would be related with the degree resistant to pathogens.