Research On Antioxidant Activity Of Curcumin And Its Inhibitory Effect On Pathogens Of Kiwi Fruit

Curcumin has a broad spectrum of antibacterial activity,and gray mold is the most important fungal disease after kiwifruit harvest.In this study,gray mold and kiwifruit were treated with curcumin,and their inhibitory effects on kiwifruit gray mold were studied.This study mainly evaluated the inhibitory effect of different concentrations of curcumin on kiwifruit gray mold and the effect on the storage quality of kiwifruit,and analyzed the inhibitory mechanism of curcumin on gray mold.The study obtained the following results:1 ? The incidence of kiwifruit and the diameter of lesions were significantly reduced after curcumin treatment.At the same time,the germination and hyphal growth of ash kiwifruit epidermis cells were significantly inhibited after curcumin treatment.Curcumin inhibited the spore germination,germ tube elongation and mycelial growth of pathogenic bacteria in vitro,and within a certain range,the inhibitory effect became more and more obvious with the increase of curcumin concentration.2?Curcumin induced ROS burst in the hyphae of B.cinerea,Leading to promoted cell apoptosis and death.Chitin deposition in hyhae was also significantly increased The use of the ROS scavenger N-acetylcysteine partially improves the effect of curcumin on hyphae.The expression level of NADPH oxidase subunit NOXR was significantly increased by curcumin,while NADPH oxidase inhibitor,diphenyliodonium chloride partially abolished curcumin-induced ROS production,indicating that curcumin induced oxidative stress in B cinerea through the NADPH oxidase-dependent pathway.3?After curcumin treatment,the three genes Bmp1,Bmp3 and Sak1 involved in vegetative growth,osmotic pressure and pathogenicity in the mitogen-activated protein kinase(MAPK)signaling pathway can be down-regulated.The results indicate that curcumin can effectively inhibit gray mold,and this inhibition may be through the regulation of osmotic pressure sensing and MAPK signaling pathway-related pathogenic genes.4 ? The content of MDA in kiwifruit decreased gradually,and the activities of antioxidant enzymes increased significantly by the addition of curcumin in a dose dependent manner.Some other storage quality indexes,such as firmness,SSC,snd TA,were not affected by curcumin.callose diposition during B.cinerea infection increased obviously in curcumin treatments.These findings indicated that curcumin controlled gray mold and promoted the storage quality of kiwifruit effectively.