UV-C enhances resistance against gray mold decay caused by Botrytis cinerea in strawberry fruit

The effect of ultraviolet C (UV-C) treatment on controlling gray mold caused by Botrytis cinerea in strawberry fruit and the possible mechanisms were investigated. The results showed that UV-C treatment significantly reduced lesion diameter and enhanced activities of chitinase (CHI), beta-1, 3-glucanase, phenylalanine ammonialyase (PAL), peroxidase (POD) and polyphenoloxidase (PPO) in strawberry fruit. Total phenolic content were also increased by UV-C treatment. The activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were also higher in UV-C treated strawberry fruit than those in control. Expression of three defense related genes such as CCR-1 allele, CAT, CHI2, PPO and PLA6 was greatly induced in UV-C treated strawberry fruit. These results suggested that UV-C treatment directly activated disease resistance against gray mold caused by B. cinerea in strawberry fruit.