PROTEASE WITH CASPASE- 3 LIKE ACTIVITY IS INVOLVED IN S. TUBEROSUM FIELD RESISTANCE TO P. INFESTANS

FERNÁNDEZ, MARÍA BELÉN; DALEO, GUSTAVO RAÚL; GUEVARA, MARÍA GABRIELA

Congreso; VIII Encuentro Latinoamericano y del Caribe de Biotecnología REDBIO-Argentina; 2013

Potato partial resistance during P. infestans infection is due to the expression of quantitative loci, being of greater durability in the field and commercially more attractive than race- specific resistance. Several proteases have been associated with horizontal resistance of potato to P. infestans infection, showing a higher accumulation in potato resistant cultivars as compared to susceptible ones. We have previously reported caspase- 3 like activity involved in potato- P. infestans interaction. The aim of this work was to correlate the caspase- 3 like activity with potato field resistance to P. infestans. Protein extracts from potato leaves from cv. Pampeana (moderately resistant) and cv. Bintje (susceptible) infected with P. infestans for 0, 1, 6, 12, 24 and 48hs were prepared. An increase in DEVDase activity was detected after 24 and 48h of infection in the resistant cultivar but not in the susceptible one. Finally, purified protease with caspase- 3 like activity induced plant tissue cell death avoiding P. infestans colonization. Moreover, this protease was able to increase 3 folds tomato cell death. Results obtained here suggest that caspase- 3 like activity could be used as a marker of field degree resistance of potato to P. infestans in breeding programs.