Increased Anion Channel Activity Is an Unavoidable Event in Ozone-Induced Programmed Cell Death

• Published in: PloS one Vol. 5; no. 10; p. e13373
• Main Authors: Kadono, Takashi, Tran, Daniel, Errakhi, Rafik, Hiramatsu, Takuya, Meimoun, Patrice, Briand, Joël, Iwaya-Inoue, Mari, Kawano, Tomonori, Bouteau, François
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 13.10.2010; Public Library of Science (PLoS)
• Subjects: Abiotic stress; Activation; Air pollution; Anion channels; Anions; Apoptosis; Apoptosis - drug effects; Arabidopsis - cytology; Arabidopsis thaliana; Biochemistry; Calcium influx; Cell Biology/Cell Signaling; Cell Biology/Cellular Death and Stress Responses; Cell Biology/Plant Cell Biology; Cell cycle; Cell death; Channel gating; Cytochrome; Daylight; Deoxyribonucleic acid; Disruption; DNA; Efflux; Environmental engineering; Enzymes; Gene expression; Granulocytes; High temperature; Hydrogen peroxide; Ion channels; Ion Channels - metabolism; Membranes; Mortality; NAD(P)H oxidase; Nitrates; Oxidases; Oxygen; Ozone; Ozone - pharmacology; Physiology; Plant Biology; Plant Biology/Plant Cell Biology; Plant Biology/Plant-Environment Interactions; Pollutants; Proteases; Reactive oxygen species; Senescence; Signal transduction; Signaling; Trends; Troposphere; Tropospheric ozone; Urban areas; VOCs; Volatile organic compounds; France
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0013373

Ozone is a major secondary air pollutant often reaching high concentrations in urban areas under strong daylight, high temperature and stagnant high-pressure systems. Ozone in the troposphere is a pollutant that is harmful to the plant. By exposing cells to a strong pulse of ozonized air, an acute cell death was observed in suspension cells of Arabidopsis thaliana used as a model. We demonstrated that O(3) treatment induced the activation of a plasma membrane anion channel that is an early prerequisite of O(3)-induced cell death in A. thaliana. Our data further suggest interplay of anion channel activation with well known plant responses to O(3), Ca(2+) influx and NADPH-oxidase generated reactive oxygen species (ROS) in mediating the oxidative cell death. This interplay might be fuelled by several mechanisms in addition to the direct ROS generation by O(3); namely, H(2)O(2) generation by salicylic and abscisic acids. Anion channel activation was also shown to promote the accumulation of transcripts encoding vacuolar processing enzymes, a family of proteases previously reported to contribute to the disruption of vacuole integrity observed during programmed cell death. Collectively, our data indicate that anion efflux is an early key component of morphological and biochemical events leading to O(3)-induced programmed cell death. Because ion channels and more specifically anion channels assume a crucial position in cells, an understanding about the underlying role(s) for ion channels in the signalling pathway leading to programmed cell death is a subject that warrants future investigation.