PROTEÍNAS ANTIFÚNGICAS CONTRA P. INFESTANS EN LOS ESPACIOS INTERCELULARES DE HOJAS DE TOMATE (Lycopersicon esculentum cerasiforme) POSIBLES DEFENSINAS DE PLANTAS / ANTIFUNGAL PROTEINS AGAINST P. INFESTANS FROM INTRACELLULAR SPACE OF TOMATO LEAVES (Lycopersicon esculentum cerasiforme) POSSIBLE DEFENSINS OF PLANTS

RESUMEN

Se aislaron y caracterizaron parcialmente proteínas antifúngicas de los espacios intercelulares de hojas de tomate Lycopersicon esculentum cerasiforme, variedad que ha mostrado resistencia en campo a Phytophthora Infestans; se observó que después de inoculación con el patógeno dichas proteínas se acumularon sistémicamente en la planta. Las proteínas identificadas mostraron características de Defensinas de plantas, una nueva familia de proteínas con bajo peso molecular, carga positiva a pH fisiológico y actividad antifúngica evaluada in vitro contra P. infestans. Los análisis electroforéticos en geles de poliacrilamida con SDS-Tricina en condiciones reductoras y no reductoras, sugirieron que están asociadas en trímeros y tetrámeros y poseen pesos moleculares de 5,2 kDa.

ABSTRACT

Antifungal Proteins from intercellular space of Tomato leaves Lycopersicon esculentum cerasiforme were isolated and partially characterized; this variety had shown resistance against Phytophthora infestans, after inoculating plants with the pathogen it was observed that these proteins were accumulated systemically. The isolated proteins be haved as plant defensins, a novel protein family, with low molecular weight, cationics at physiological pH and Antifungal Activity in vitro evaluated against P. infestans. Electrophoretic analyses in SDS Tricine-PAGE, under reducing and non-reducing conditions suggested that, they were associated as trimers and tetramers; and have molecular weights of 5,2 kDa.