RAPISARDA Viviana Andrea
congresos y reuniones científicas
Membrane damage induced by an oxidative treatment against P. digitatum, agent of citrus green mold
CERIONI, L.; VOLENTINI, S. I.; PRADO, F. E.; RAPISARDA, V. A.; RODRÍGUEZ-MONTELONGO, L.
San Miguel de Tucumán, Tucumán, Argentina
Congreso; XLV Annual Meeting of SAIB; 2009
Peroxides produces free radicals through the Fenton reaction, catalyzed by metals like copper or iron. These radicals lead to the damage of lipids, carbohydrates, proteins, and nucleic acids, affecting the cellular integrity. In our laboratory, an oxidative treatment (OT) to inhibit the growth of Penicillium digitatum conidia has been developed. The OT consists in a preincubation with 10 ppm NaClO followed by incubation with 6 mM CuSO4 and several H2O2 concentrations. Here, we analyze the effects of OT on conidia germination, mycelium growth and membrane integrity of fungi. Conidia germination was totally inhibited by OT using 100 mM H2O2. In addition, mycelium growth was more sensitive to the treatment than conidia, resulting inhibited at 50 mM H2O2. We determined the degree of membrane damage by Sytox Green dye, which only enters into cells with altered membranes. The assay was applied on conidia and mycelium samples after exposure to the OT. The percentages of fluorescent and non-viable conidia were proportional increased with H2O2 concentration. When P. digitatum mycelium was treated with lethal OT, there was broad dye incorporation. Our results suggest that the OT based on the combination of NaClO, CuSO4 and H2O2 alters integrity of fungal membrane, which could be related with the lethality of the treatment.