title: Arabidopsis GRI is involved in the regulation of cell death induced by extracellular ROS.
abstract: Reactive oxygen species (ROS) have important functions in plant stress responses and development. In plants, ozone and pathogen infection induce an extracellular oxidative burst that is involved in the regulation of cell death. However, very little is known about how plants can perceive ROS and regulate the initiation and the containment of cell death. We have identified an Arabidopsis thaliana protein, GRIM REAPER (GRI), that is involved in the regulation of cell death induced by extracellular ROS. Plants with an insertion in GRI display an ozone-sensitive phenotype. GRI is an Arabidopsis ortholog of the tobacco flower-specific Stig1 gene. The GRI protein appears to be processed in leaves with a release of an N-terminal fragment of the protein. Infiltration of the N-terminal fragment of the GRI protein into leaves caused cell death in a superoxide- and salicylic acid-dependent manner. Analysis of the extracellular GRI protein yields information on how plants can initiate ROS-induced cell death during stress response and development.
authors.affiliation: Plant Biology, Department of Biological and Environmental Sciences, University of Helsinki, P.O.B. 65, FI-00014 Helsinki, Finland.
authors.forename: Michael
authors.initials: M
authors.lastname: Wrzaczek
authors.forename: Mikael
authors.initials: M
authors.lastname: Brosché
authors.forename: Hannes
authors.initials: H
authors.lastname: Kollist
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kangasjärvi
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000502:physiology*; D016923:Cell Death; D010126:Ozone; D010446:Peptide Fragments; D018515:Plant Leaves; D017382:Reactive Oxygen Species / Q000494:pharmacology*; D020156:Salicylic Acid; D013481:Superoxides
chemical_list: D029681:Arabidopsis Proteins; D010446:Peptide Fragments; D017382:Reactive Oxygen Species; D013481:Superoxides; D010126:Ozone; D020156:Salicylic Acid