Citotoxic activity of an aspartic peptidase from Salpichroa origanifolia against the infection caused on green zucchini (Cucurbita maxima, var. Zapallito) by Phytophthora capsici

Abstract

Phytophthora capsici is a phytopathogenic
agent that causes significant losses in crops of economic
interest. The chemicals traditionally used to fight these
pathogens cause adverse effects on health and the
environment. Native plants represent an alternative source
of natural antifungal metabolites. In our laboratory we have
studied a perennial herb, Salpichroa origanifolia, native to
the northern and central Argentina whose ovoid fruits are
edible berry. An aspartyl peptidase from the crude extract
of the ripe fruit of this species was purified by ion exchange
chromatography using a batch process. The enzyme was
called salpichroín. In this work the antifungal effect of the
aspartyl peptidase on P. capsici was studied. It was obtained
that salpichroín had a high cytotoxic effect in vitro on strains
of P. capsici (MIC: 1.2 μmol L-1). To evaluate the enzyme
effect on the development of P. capsici in vivo, inoculation
controlled bioassays on green zucchini (Cucurbita maximum
var Zapallito) were performed. The fruit inoculated with the
phytopathogen and salpichroín remained asymptomatic for
seven days.