Research Article
Geethu C, Sumna S, Resna AK
Abstract
Pythium myriotylum Drechsler (Stramenophila, Oomycete) is a necrotrophic phytopathogen causing significant economic losses in many crop plants. Previous research has indicated paromomycin, an aminoglycoside antibiotic produced by Streptomyces spp., as a potent inhibitor of Pythium spp. Present study focuses on evaluating the mode of action of paromomycin on the zoospores and hyphae of P. myriotylum. Lytic effects of paromomycin were observed on both P. myriotylum zoopsores, as well as on hyphae in a concentration-dependent manner. Time and concentration-dependent release of cellular materials from hyphae in presence of paromomycin provided evidences on hyphal lysis, as the mechanistic basis for its anti-Pythium activity. This was further confirmed by electron microscopic evaluation of paromomycin-treated and untreated hyphae, indicating that paromomycin produced severe deformities to the hyphae.