Role of Exopolygalacturonase-Related Genes in Potato- Interaction.

is a hemibiotrophic pathogen responsible for great losses in dicot crop production. An gene (VDAG_03463,) identified using subtractive hybridization/cDNA-AFLP, showed higher expression levels in highly aggressive than in weakly aggressive isolates. We used a vector-free split-marker recombination method with PEG-mediated protoplast to delete the gene in This is the first instance of using this method for transformation. Only two PCR steps and one transformation step were required, markedly reducing the necessary time for gene deletion. Six mutants were identified. expressed more in the highly aggressive than in the weakly aggressive isolate in response to potato leaf and stem extracts. Its expression increased in both isolates during infection, with higher levels in the highly aggressive isolate at early infection stages. The disruption of did not influence virulence, nor did it affect total exopolygalacturonase activity in . Full genome analysis showed 8 more genes related to polygalacturonase/pectinase activity in . Transcripts of increased in the mutant in response to potato leaf extracts, compared to the wild type. The expression pattern of those eight genes showed similar trends in the mutant and in the weakly aggressive isolate in response to potato extracts, but without the increase of in the weakly aggressive isolate to leaf extracts. This indicated that the mutant of compensated by the suppression of ExoPG by activating other related gene.