title: Organelle redox autonomy during environmental stress.
abstract: Oxidative stress is generated in plants because of inequalities in the rate of reactive oxygen species (ROS) generation and scavenging. The subcellular redox state under various stress conditions was assessed using the redox reporter roGFP2 targeted to chloroplastic, mitochondrial, peroxisomal and cytosolic compartments. In parallel, the vitality of the plant was measured by ion leakage. Our results revealed that during certain physiological stress conditions the changes in roGFP2 oxidation are comparable to application of high concentrations of exogenous H2 O2 . Under each stress, particular organelles were affected. Conditions of extended dark stress, or application of elicitor, impacted chiefly on the status of peroxisomal redox state. In contrast, conditions of drought or high light altered the status of mitochondrial or chloroplast redox state, respectively. Amalgamation of the results from diverse environmental stresses shows cases of organelle autonomy as well as multi-organelle oxidative change. Importantly, organelle-specific oxidation under several stresses proceeded cell death as measured by ion leakage, suggesting early roGFP oxidation as predictive of cell death. The measurement of redox state in multiple compartments enables one to look at redox state connectivity between organelles in relation to oxidative stress as well as assign a redox fingerprint to various types of stress conditions.
authors.affiliation: Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel, 7610001.
authors.forename: Avishay
authors.initials: A
authors.lastname: Bratt
authors.affiliation: Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel, 7610001.
authors.forename: Shilo
authors.initials: S
authors.lastname: Rosenwasser
authors.affiliation: Chemical Signaling Lab, University of Bonn, Bonn, Germany, D-53113.
authors.forename: Andreas
authors.initials: A
authors.lastname: Meyer
authors.affiliation: Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel, 7610001.
authors.forename: Robert
authors.initials: R
authors.lastname: Fluhr
mesh_terms: D017360:Arabidopsis; D003681:Dehydration; D049452:Green Fluorescent Proteins; D006861:Hydrogen Peroxide; D015388:Organelles / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress
chemical_list: D049452:Green Fluorescent Proteins; D006861:Hydrogen Peroxide
keywords: Arabidopsis; glutathione; organelle redox state; oxidative stress; plant stress; redox state