Pre-storage treatment of mechanically-injured green pepper (Capsicum annuum L.) fruit with putrescine reduces adverse physiological responses

Green peppers are vulnerable to mechanical damage during harvesting and postharvest storage and transportation that significantly decreases their quality and economic value. In the present study, the effects of a pre-storage exogenous application of 1 mmol L−1 putrescine (Put) was assessed by the postharvest physiology indicators of two cultivars of mechanically-injured green pepper ('Nongda 24' and 'Jingtian 3') stored at 20 °C. Results indicated that, compared to control, Put treatment effectively maintained the quality of the green peppers by suppressing the change in fruit color from green to red, maintaining higher fruit firmness, decreasing electrolyte leakage, reducing the degradation of vitamin C and chlorophyll, and inhibiting the accumulation of malondialdehyde. The relative gene expression and enzyme activity of peroxidase, catalase, and ascorbate peroxidase were enhanced by Put. The collective data indicates that Put reduces the adverse physiological changes in pepper fruits caused by mechanical injury. The use of Put may provide a method to reduce food wastage and economic losses in the production and marketing of green peppers.