The ascorbate-gluathione cycle and related redox signals in plant-pathogen interactions

Abstract

Reactive oxygen species (ROS) in plants are known to accumulate during biotic stress and different cellular compartments respond to them by a distinct antioxidant repertoire. The ascorbate-glutathione (AsA-GSH) cycle serves as the main antioxidant pathway in plant cells linking the protection against ROS to redox-regulated plant defence. This chapter makes a selective overview on the compartment-specific role of the AsA-GSH cycle constituents in the process of sensing and transducing signals and in regulation of nuclear gene expression in response to pathogens. The focus of this review is the specific interplay between ascorbate and glutathione, the two major cellular redox determinants. The potent biological significance of the effects mediated by ascorbate and glutathione in plant-pathogen interactions has been considered with reference to the lifestyle of the invading pathogen and to the local versus systemic defence.