Benzo-thiadiazole-7-carbothioic Acid S-methyl Ester does not protect Melon Fruits against Fusarium pallidoroseum Infection but Induces Defence Responses in Melon Seedlings

The present study investigated the potential of benzothiadiazole-7-carbothioic acid S-methyl ester (BTH) to protect postharvest melons var. Orange Flesh from the fruit rot caused by Fusarium pallidoroseum. It was noticed that melon fruits immersed in BTH and postinoculated with the fungus presented the same pattern of disease incidence ⁄ severity and activity of the defence-related enzymes superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, phenylalanine ammonia-lyase, and b-1,3-glucanase of controls, indicating that BTH was ineffective in protecting melons from the fruit rot disease. However, the preflowering application of BTH in melon seedlings induced stunted growth, probably related to enhanced lignification which is related to the plant cell wall reinforcement and increase of resistance against invading pathogens, and alterations of the activity of the studied defence-related enzymes in comparison with controls, suggesting that this strategy could probably be effective for the control of the postharvest rot of melon fruits through activation of systemic resistance.