Ver-A Exhibits Broad-Spectrum Antifungal Activity
In vitro antifungal experiments demonstrate that Ver-A can inhibit the sexual mating of sugarcane smut spores at a concentration of 8 μg/mL. Additionally, it shows inhibitory activity against Aspergillus fumigatus and Candida albicans , with minimum inhibitory concentrations of 16 and 4 μg/mL, respectively. These results indicate that Ver-A possesses broad-spectrum antifungal activity.
Pot Efficacy of Ver-A Against Sugarcane Smut Disease
To evaluate the effectiveness of Ver-A against sugarcane smut disease, we conducted pot experiments. On day 20 post-inoculation, microscopic examination of sugarcane stem samples revealed mycelium in tissues inoculated with MAT-1 and MAT-2 spores. However, samples from the treatment group displayed no smut symptoms and contained only haploid spores. By day 120 post-inoculation, 80% of the plants inoculated with MAT-1 and MAT-2 spore suspension developed black spike symptoms, whereas the incidence in the P-6 ethyl acetate extract group significantly decreased to 37%, demonstrating the efficacy of fermentation extract in controlling sugarcane smut.
Mechanism of Ver-A on inhibiting sexual mating of S. scitamineum
Using real-time quantitative PCR (RT-qPCR), we quantitatively analyzed nine relevant genes associated with the pathogenicity of the sugarcane smut pathogen and the sexual mating process. The results showed that treatment with Ver-A significantly downregulated the expression levels of the mfa1 and pra1 genes, while the expression levels of bE2 , bW1 , bW2 , mfa2 , and pra2 were significantly increased. Since the mfa and pra genes are responsible for pheromone synthesis and the recognition and regulation of mating types, Ver-A disrupts the expression of these genes, thereby blocking the recognition and mating of the sugarcane smut pathogen's haploid spores, ultimately inhibiting the formation of invasive hyphae.
See the article:
Interference with sexual mating of Sporisorium scitamineum by verrucarin A isolated from Paramyrothecium sp.
25-Nov-2024