Curcumin inhibits gray mold development in kiwifruit by targeting mitogen-activated protein kinase (MAPK) cascades in Botrytis cinerea

Curcumin is a promising antifungal agent because of its wide range of antifungal activity. In the present study, the effect of curcumin on gray mold (Botrytis cinerea) in kiwifruit was evaluated. Results showed that spore germination, germ tube elongation, and mycelial growth of B. cinerea were significantly suppressed by curcumin in a dose dependent manner. Mycelium treated with curcumin exhibited a higher sensitivity to osmotic stress, and the ability of hyphae to penetrate plant cell walls was also inhibited. Three mitogen-activated protein kinase (MAPK) genes, Bmp1, Bmp3, and Sak1, involved in vegetative growth, osmotic stress response, and pathogenicity, were down-regulated by curcumin. The application of curcumin up to 400 mg L-1 significantly delayed disease development in kiwifruit. These results indicate that curcumin can effectively inhibit gray mold in kiwifruit; and this effect involves alterations in the sensitivity of B. cinerea to pathogenicity-associated MAPK cascades.