Microbial elicitors or attempted infection with an avirulent pathogen strain causes the rapid production of reactive oxygen intermediates. We report here that H2O2 from this oxidative burst not only drives the cross-linking of cell wall structural proteins, but also functions as a local trigger of programmed death in challenged cells and as a diffusible signal for the induction in adjacent cells of genes encoding cellular protectants such as glutathione S-transferase and glutathione peroxidase. Thus, H2O2 from the oxidative burst plays a key role in the orchestration of a localized hypersensitive response during the expression of plant disease resistance.
Bibliographical noteFunding Information:
Correspondence should be addressed to C. L. We thank Cindy Doane for preparation of the manuscript, M. Hahn for elicitors and soybean cell cultures, N. Keen for bacterial strains, A. Cross for antibodies, and J. Fleck, Ft. Nagao, and R. Vierstrafor probes. A. L. wassupported in part by a Binational Agricultural Research and Development Fund fellowship. R. T. was supported by fellowships from the Deutscher Akademischer Austauschdienst (North Atlantic Treaty Organization program) and Deutsche Forschungsgemeinschaft. This research was supported by grants to C. L. from the National Science Foundation (IBN-9104551) and the Noble Foundation.