The apoplastic oxidative burst in response to biotic stress in plants: a three-component system.

The oxidative burst, the generation of reactive oxygen species (ROS) in response to microbial pathogen attack, is a ubiquitous early part of the resistance mechanisms of plant cells. It has also become apparent from the study of a number of plant-pathogen interactions and those modelled by elicitor treatment of cultured cells that there may be more than one mechanism operating. However, one mechanism may be dominant in any given species.

Early signalling events in the apoplastic oxidative burst in suspension cultured French bean cells involve cAMP and Ca.

•  Modulators of cAMP, calcium and G proteins were used to treat bean (Phaseolus vulgaris) cells before addition of an elicitor from Colletotrichum lindemuthianum in order to elucidate the early steps of signal transduction leading to the production of the apoplastic oxidative burst. •  Hydrogen peroxide production by elicited bean cells was monitored with luminol-or xylenol-orange-based assays. •  Pretreatment with forskolin, dibutyryl cAMP or the Ca ionophore A23187 enhanced the production of reactive oxygen species (ROS).