Interplay between ascorbic acid and lipophilic antioxidant defences in chloroplasts of water-stressed Arabidopsis plants.
The effects of low ascorbic acid (Asc) on lipophilic antioxidant defences and lipid peroxidation in chloroplasts were evaluated in the vtc-1 mutant of Arabidopsis thaliana, which had an Asc deficiency in chloroplasts of ca. 60%. Although low Asc did not cause oxidative stress in optimal growth conditions, it increased malondialdehyde levels in chloroplasts by ca. 60%, and reduced alpha-tocopherol and beta-carotene by ca. 85% and 40%, respectively, in water-stressed (WS) mutants. These results are indicative of the interplay between Asc and lipophilic antioxidants in chloroplasts of WS plants in vivo, and show that Asc contributes to the protection of thylakoid membrane lipids from oxidation in stressed plants.
Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 645, E-08028 Barcelona, Spain. smunne@porthos.bio.ub.es
Sergi
S
Munné-Bosch
Leonor
L
Alegre
D000975:Antioxidants / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000378:metabolism; D018384:Oxidative Stress; D014867:Water; D024502:alpha-Tocopherol / Q000378:metabolism; D019207:beta Carotene / Q000378:metabolism
D000975:Antioxidants; D019207:beta Carotene; D014867:Water; D009713:Nucleotidyltransferases; C026917:mannose 1-phosphate guanylyltransferase; D024502:alpha-Tocopherol; D001205:Ascorbic Acid