Hydrogen sulfide enhances loquat fruit resistance to anthracnose by regulating phenylpropane metabolism and antioxidant system.

Anthracnose represents one of the most significant diseases affecting postharvest loquats. In this research, we investigated the influences of hydrogen sulfide (H2S) on postharvest disease from three perspectives: pathogenesis-related (PR) proteins, phenylpropane metabolism and reactive oxygen species metabolism. The results demonstrated that H2S remarkably reduced the disease incidence and lesion diameter of loquat fruit (At day 4 and 6, the disease incidence rate of the treatment group was 57.14 % and 77.65 % of the control group, and the lesion diameter was 34.89 % and 23.91 % less than the control group, respectively), and delayed the decline of fruit quality compared with the control. Furthermore, H2S activated PR proteins, induced the accumulation of disease resistance-related substances through regulating the activity of enzymes related to phenylpropane metabolism, and promoted the accumulation of antioxidant substances and increased the activity of antioxidant enzymes through regulating ROS metabolism. In conclusion, the present study demonstrated that H2S fumigation provides a novel, effective strategy for controlling postharvest anthracnose in loquats.