SILVER NANOPARTICLES: A PROMISING APPROACH TO CONTROL LEMONS POSTHARVEST MOLDS

BAIGORRIA CG; DEBES MA; CERIONI L; LEDESMA A; D'ALMEIDA RE; RAPISARDA VA; VOLENTINI SI

Jornada; XL JORNADAS CIENTÍFICAS; 2023

Lemon production in Tucumán is a great economic activity, but suffer important losses due to postharvest fungal diseases, such as green, blue, and sour rot caused by Penicillium digitatum (PDS), P. italicum (PIS) and Geotrichum citri-aurantii (GC), respectively. To control these decays, fungicides have been used but their continuous application has led to resistance. So, new alternative methods are required. Nanoparticles have been reported as potential antimicrobials due to their high surface-to-volume ratio, which enhances their interaction with microorganisms. In this study, we investigated the antifungal action of silver nanoparticles (NPs-Ag) as a novel alternative for controlling local isolates of fungal pathogens for lemons. NPs-Ag were synthesized by chemically proceed and characterized using several analytical methods. To evaluate antifungal activity, conidial suspensions of PDS, PIS, and GC, adjusted to 106 CFU/mL, were exposed to different concentrations of NPs-Ag. The minimum fungicidal concentration was 10 µg/mL, after 24h incubation. To study action mechanism, the membrane permeability, reactive oxygen species (ROS) production and conidia cellular ultrastructure were determinate. It was demonstrated that NPs-Ag permeabilize the plasma membrane and disrupt cellular organization. Furthermore, the NPs-Ag cytotoxicity was evaluated using the nematode C. elegans. It was shown that they do not affect survival up to 96 hours, although a reduction in reproduction with a decrease in egg deposition was observed. Additionally, when the NPs-Ag in vivo action was assay on artificially infected lemons, 1000 µg/mL of NPs-Ag could be reduced the mold incidence. These results present a promising approach to NPs-Ag application to control fungal postharvest diseases on lemons.