Bax-induced cell death in tobacco is similar to the hypersensitive response.
Bax, a death-promoting member of the Bcl-2 family of proteins, triggered cell death when expressed in plants from a tobacco mosaic virus vector. Analysis of Bax deletion mutants demonstrated a requirement for the BH1 and BH3 domains in promoting rapid cell death, whereas deletion of the carboxyl-terminal transmembrane domain completely abolished the lethality of Bax in plants. The phenotype of cell death induced by Bax closely resembled the hypersensitive response induced by wild-type tobacco mosaic virus in tobacco plants carrying the N gene. The cell death-promoting function of Bax in plants correlated with accumulation of the defense-related protein PR1, suggesting Bax activated an endogenous cell-death program in plants. In support of this view, both N gene- and Bax-mediated cell death was blocked by okadaic acid, an inhibitor of protein phosphatase activity. The ability of Bax to induce cell death and a defense reaction in plants suggests that some features of animal and plant cell death processes may be shared.
Department of Virology, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, United Kingdom.
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D000818:Animals; D017209:Apoptosis; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D051379:Mice; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D019590:Nucleocapsid Proteins / Q000235:genetics / Q000502:physiology; D019319:Okadaic Acid / Q000494:pharmacology; D010641:Phenotype; D010947:Plants, Toxic; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2; D014026:Nicotiana / Q000166:cytology* / Q000502:physiology*; D014027:Tobacco Mosaic Virus / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D051028:bcl-2-Associated X Protein
C494827:Bax protein, mouse; D008164:Luminescent Proteins; D019590:Nucleocapsid Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D049452:Green Fluorescent Proteins; D019319:Okadaic Acid