Role of Reactive Oxygen Species against Pathogens in Relation to Postharvest Disease of Papaya Fruit

Reactive oxygen species (ROS) play an active role in plant defense. Polyphenol oxidase (PPO) and peroxidase (POD) participate the synthesis of phytoalexins. The comparative activities ROS, including hydrogen peroxide (H2O2), superoxide anions (O2−), hydroxyl radicals (·OH), against fungal pathogen Colletotrichum gloeosporioides from papaya fruit were evaluated. effects ROS on PPO POD inoculated with C. development natural decay intact also investigated. ·OH was most effective inhibiting conidial germination mycelial growth vitro. However, 20 or 30 mM H2O2 exhibited best control three treatments at ameliorating disease symptoms associated highest levels fruit. Furthermore, negatively correlated index. Overall, can induce resistance owing to enhanced POD. Treatment significantly reduced incidence semi-commercial experiment, which could make it a potential alternative manner postharvest