Nitric oxide postharvest treatment improves disease resistance in ginger by regulating ROS homeostasis, phenylpropionic acid metabolism and S-nitrosylation levels.

Nitric oxide (NO), as a widely used preservative for fruit and vegetables, can effectively extend shelf life and improve disease resistance. Fusarium solani (F. solani) causes a soft rot that seriously impacts the quality and production of ginger. Thus, control of diseases in postharvest ginger is necessary. In this study, 1 mM sodium nitroprusside (SNP, NO donor) was used to explore the disease resistance of postharvest ginger after infection with F. solani. We found that NO inhibited further infestation of F. solani in ginger and had a direct inhibition of F. solani growth in vitro. NO reduced the damage of F. solani, activated the activity of disease-resistant enzymes, increased the content of antioxidants and phenylalanine metabolites. Besides, NO increased endogenous NO level and SNO content and down-regulated GSNOR activity and transcriptional expression, implicating that S-nitrosylation might be involved in NO-enhanced disease resistance in ginger. Thus, NO enhances the ginger resistance against F. solani by regulating ROS homeostasis, phenylpropionic acid metabolism, endogenous NO content and S-nitrosylation level. Thus, NO treatment was found to be beneficial in improving disease resistance in ginger during storage.