title: Constitutive caspase-like machinery executes programmed cell death in plant cells.
abstract: The morphological features of programmed cell death (PCD) and the molecular machinery involved in the death program in animal cells have been intensively studied. In plants, cell death has been widely observed in predictable patterns throughout differentiation processes and in defense responses. Several lines of evidence argue that plant PCD shares some characteristic features with animal PCD. However, the molecular components of the plant PCD machinery remain obscure. We have shown that plant cells undergo PCD by constitutively expressed molecular machinery upon induction with the fungal elicitor EIX or by staurosporine in the presence of cycloheximide. The permeable peptide caspase inhibitors, zVAD-fmk and zBocD-fmk, blocked PCD induced by EIX or staurosporine. Using labeled VAD-fmk, active caspase-like proteases were detected within intact cells and in cell extracts of the PCD-induced cells. These findings suggest that caspase-like proteases are responsible for the execution of PCD in plant cells.
authors.affiliation: Department of Plant Sciences, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Elbaz
authors.forename: A
authors.initials: A
authors.lastname: Avni
authors.forename: M
authors.initials: M
authors.lastname: Weil
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D017209:Apoptosis; D006690:Bisbenzimidazole; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D002457:Cell Extracts; D002478:Cells, Cultured; D003470:Culture Media; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D005456:Fluorescent Dyes; D013194:Staining and Labeling / Q000379:methods; D019311:Staurosporine / Q000494:pharmacology; D014026:Nicotiana / Q000166:cytology / Q000201:enzymology
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D061945:Caspase Inhibitors; D002457:Cell Extracts; D003470:Culture Media; D015853:Cysteine Proteinase Inhibitors; D005456:Fluorescent Dyes; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C417985:butyloxycarbonyl-aspartyl-fluoromethyl ketone; D020169:Caspases; D019311:Staurosporine; D006690:Bisbenzimidazole