Enzymatic, but not non-enzymatic, 1O2-mediated peroxidation of polyunsaturated fatty acids forms part of the EXECUTER1-dependent stress response program in the flu mutant of Arabidopsis thaliana

摘要: The conditional flu mutant of Arabidopsis accumulates excess amounts protochlorophyllide within plastid membranes in the dark and generates singlet oxygen upon light exposure. By varying length period, level photosensitizer may be modulated, conditions have been established that either endorse cytotoxicity (1)O(2) or reveal its signaling role. Two criteria used to distinguish between these two modes activity (1)O(2): impact EXECUTER1 mutation prevalence non-enzymatic enzymatic lipid peroxidation. During illumination etiolated seedlings, toxic effects prevail peroxidation proceeds rapidly. In contrast, light-grown plants were subjected an 8 h dark/light shift, occurred almost exclusively enzymatically. resulting oxidation product, 13-hydroperoxy octadecatrienoic acid (13-HPOT), serves as a substrate for synthesis 12-oxo phytodienoic (OPDA) jasmonic (JA), both which are known control various metabolic developmental processes plants. Inactivation protein abrogates not only (1)O(2)-mediated cell death growth inhibition plants, but also However, inactivation jasmonate biosynthesis aos/flu double does affect death. Hence, JA OPDA do act second messengers during signaling, form integral part stress-related cascade activated by encompasses several pathways abiotic biotic stressors.