Involvement of lipoxygenase, lipoxygenase pathway volatiles, and lipid peroxidation during the hypersensitive reaction of pepper leaves to Xanthomonas campestris pv. vesicatoria.

摘要

A study was carried out to determine the changes in lipoxygenase activity and protein levels, levels of peroxidation and the production of lipid derived volatiles in Capsicum annuum (cv. Early Calwonder-10R) leaves after inoculation with an avirulent race of X. c. pv. vesicatoria [Xanthomonas vesicatoria]. Activity of lipoxygenase increased 8-12 h after inoculation (collapse phase of hypersensitive response) but the protein level decreased. When only a half of a leaf was inoculated with the bacterium the levels of lipoxygenase activity increased in both inoculated and non-inoculated halves of the leaves, but protein levels decreased only in the inoculated half. The incompatible interaction during the collapse phase of the hypersensitive response was increased by the evolution of some volatile compounds from the lipoxygenase pathway. Lipid peroxidation increased during the advanced stages of the hypersensitive reaction. It was observed that the oxidative index was only increased in the glycolipidfraction.