2 Agronomy College,
Gansu Agricultural University, Lanzhou 730070, China
Abstract: The antifungal mechanism of potato glycoalkaloids was
studied using a sensitive species, Fusarium solani . The effects
of potato glycoalkaloid extract on the ultrastructure, membrane
permeability, and contents of reducing sugar, soluble sugar, soluble
protein, and mycelial fat of F. solani were determined. Potato
glycoalkaloids significantly affected F. solani mycelial
morphology, resulting in bubbly mycelial cell walls, incomplete outer
layer, discontinuous cell membrane, disorganized structures of
mitochondria and other organelles, and visible leakage of cell contents.
Investigation of material metabolism indicated that potato
glycoalkaloids disrupted selective permeability of mycelial cell
membranes; caused massive exudation of internal lipids, proteins, and
carbohydrates; hindered hydrolysis of reducing sugar; affected nutrient
absorption and utilization; and inhibited decomposition metabolism of
mycelia. Thus, potato glycoalkaloids altered the morphology of fungal
mycelia, destroyed cell membrane structure, increased mycelial cell
membrane permeability, and caused cell contents leakage, resulting in
effective inhibition of growth and metabolism of plant pathogenic fungi
and so could decrease the occurrence of plant disease.
Keywords:Potato glycoalkaloids;Fusarium
solani ; Antifungal mechanism