Characterization of secreted modifying enzymes from the late blight pathogen Phytophthora infestans
C. SCHOINA (1), K. Bouwmeester (2), M. Seidl (2), S. Rodenburg (2), H. Meijer (2), F. Govers (2) (1) Wageningen Univercity, Netherlands; (2) Wageningen University, Netherlands

Phytophthora infestans is a notorious plant pathogenic oomycete that causes late blight in potato and tomato. The molecular mechanisms exploited by P. infestans for establishing host colonization are poorly understood. In several cases, proteases produced by pathogens have been found to be involved in virulence. The P. infestans genome encodes a large number of proteases with unknown functions. We focus on two types of proteases that may have a role in P. infestans virulence namely metalloproteases (MPs) and aspartic proteases (APs). In other pathogens, MPs were found to contribute to virulence, such as Leishmania GP63 and Erwinia amylovora PtrA. Moreover, in the malaria pathogen Plasmodium, the AP plasmepsin V was shown to function in the export of effectors into host cells. To study the potential role of P. infestans MPs a gene inventory was made based on genome mining and predicted gene models were verified using ESTs and transcriptomics data. This resulted in a total of 104 P. infestans MPs that could be classified into 20 families. Analyses of the MP domain composition showed that 27 contain a N-terminal signal peptide and are thus potentially secreted. Currently we are investigating if these secreted MPs have an effect on virulence by transient expression of MPs in N. benthamiana and subsequent infection with Phytophthora. For the functional analyses of APs we focus on the plasmepsin V homologs PiAP10, PiAP11 and PiAP12. Silencing of APs in P. infestans and enzyme activity assays may reveal their role in pathogen virulence and host manipulation.

Abstract Number: P9-301
Session Type: Poster