Inactivation of baculovirus by quinones formed in insect-damaged plant tissues

The infectivity of the nuclear polyhedrosis virus, HzSNPV to Heliothis zea was significantly reduced when viral occlusion bodies were exposed to the plant phenolic chlorogenic acid in the presence of polyphenol oxidase. Chlorogenic acid is rapidly oxidized to the ortho-quinone, chlorogenoquinone, by foliar polyphenol oxidases of the tomato plant, Lycopersicon esculentum, when foliage is damaged during feeding by larval H. zea. Our results indicate that chlorogenoquinone, a powerful oxidizing agent, covalently binds to the occlusion bodies of HzSNPV and significantly reduces their digestibility and solubility under alkaline conditions. This binding is proposed to interfere with the infection process by impairing the release of infective virions in the midgut.