Identification of Virulence Proteases from Botrytis cinerea by Cross-Proteolysome Analysis in Fungi

TEN HAVE A

Mar del Plata

Conferencia; XLIII Reunión Anual de la SAIB; 2007

SAIB

Although proteases secreted by plant pathogens are envisaged to degrade structural and Pathogenesis Related plant proteins, it is difficult to identify proteases as virulence factor. Comparing genomes from fungi with a different phylogeny and/or lifestyle provides a new tool for identifying genes under natural selection, such as virulence protease genes. I compared the proteolysome (i.e. all known proteases) from ascomycete plant pathogen Botrytis cinerea (Bc) with other fungal proteolysomes in order to find virulence proteases. A genome-BlastP with the Neurospora crassa proteolysome (MEROPS) as a query identified 250 Bc sequences of which 195 were confirmed as putative protease. The corresponding sequences were used for a specific and saturating, manual and iterative BlastP analysis against the genomes of seven other ascomycetes and one basidiomycete. Comparison showed that Bc and related pathogen Sclerotinia sclerotiorum are poor in certain basic and rich in certain acid proteases, corresponding with the observed acidification during pathogenesis. Molecular evolutionary studies (e.g. Phylogeny, McDonald-Kreitman tests) are performed to determine which acid proteases are likely to act in virulence. Preliminary results suggest a horizontal gene transfer has taken place. These and other to be obtained results will be discussed in terms of evolution, pathogenesis and competition.