Singlet Oxygen-Induced Cell Death in Arabidopsis under High-Light Stress Is Controlled by OXI1 Kinase. Issue 3 (8th January 2016)

• Record Type: Journal Article
• Authors: Shumbe, Leonard; Chevalier, Anne; Legeret, Bertrand; Taconnat, Ludivine; Monnet, Fabien; Havaux, Michel
• Is Part Of: Plant physiology. Volume 170:Issue 3(2016)
• Page Start: 1757
• Page End: 1771
• Publication Date: 2016-01-08
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.15.01546
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : The AGC kinase OXI1 regulates 1 O2 -induced cell death in plants exposed to excess light energy. Abstract: Studies of the singlet oxygen ( 1 O2 )-overproducing flu and chlorina1 ( ch1 ) mutants of Arabidopsis ( Arabidopsis thaliana ) have shown that 1 O2 -induced changes in gene expression can lead to either programmed cell death (PCD ) or acclimation. A transcriptomic analysis of the ch1 mutant has allowed the identification of genes whose expression is specifically affected by each phenomenon. One such gene is OXIDATIVE SIGNAL INDUCIBLE1 ( OXI1 ) encoding an AGC kinase that was noticeably induced by excess light energy and 1 O2 stress conditions leading to cell death. Photo-induced oxidative damage and cell death were drastically reduced in the OXI1 null mutant ( oxi1 ) and in the double mutant ch1*oxi1 compared with the wild type and the ch1 single mutant, respectively. This occurred without any changes in the production rate of 1 O2 but was cancelled by exogenous applications of the phytohormone jasmonate. OXI1-mediated 1 O2 signaling appeared to operate through a different pathway from the previously characterized OXI1-dependent response to pathogens and H2 O2 and was found to be independent of the EXECUTER proteins. In high-light-stressed plants, the oxi1 mutation was associated with reduced jasmonate levels and with the up-regulation of genes encoding negative regulators of jasmonate signaling and PCD . Our results show that OXI1 is a new regulator of 1 O2 -induced PCD, likely acting upstream of jasmonate.