Fungal and plant proteases interaction.

SUELDO, D.; ANDREU, A.;DALEO, G.; GUEVARA, M.; OLIVIERI, F

San Diego, California. USA

Congreso; American Phytopathological Society; 2007

In plant-pathogen interactions the role of proteases from microorganism and host has been very well documented. However, a possible interaction between them has not been studied. F. solani f. sp. eumartii (F. eumartii) causes dry rot, an economically important disease in potato (Solanum tuberosum). Penetration and colonization of plant tissues by this fungus requires the secretion of hydrolases; one of them is an extracellular serin protease (FESP). On the other hand, potato aspartic proteases (StAPs) isolated from intercellular washing fluids (IWF) have been reported with antimicrobial activity. Preliminary results suggested that FESP and StAP1 could interact in F. eumartii infected potato tubers. The aim of this work was to analyze StAP1 and FESP expression at different times of infection and their proteolytic interaction. After infection, expression of StAP1 increased up to 36 hours and decreased after that, while the appearance of bands of lower molecular weight was observed, suggesting possible degradation. On the contrary, FESP activity increases from 48 hs to 12 days after infection. In vitro assays show that partially purified FESP is able to degrade StAP1. These results suggest that StAP1-FESP proteolytic interaction could be involved in the Fusarium-potato phatosystem. Future assays to prove molecular interaction between these proteases are in progress