Replacement of alpha-tocopherol by beta-tocopherol enhances resistance to photooxidative stress in a xanthophyll-deficient strain of Chlamydomonas reinhardtii.

ABSTRACT: Tocopherols (vitamin E) comprise a class of lipid-soluble antioxidants synthesized only in plants, algae, and some cyanobacteria. The majority of tocopherols in photosynthetic cells is in the alpha form, which has the highest vitamin E activity in humans, whereas the beta, gamma, and delta forms normally account for a small percentage of total tocopherols. The antioxidant activities of these forms of tocopherol differ depending on the experimental system, and their relative activities in vivo are unclear. In a screen for suppressors of the xanthophyll-deficient npq1 lor1 double mutant of Chlamydomonas reinhardtii, we isolated a vte3 mutant lacking alpha-tocopherol but instead accumulating beta-tocopherol. The vte3 mutant contains a mutation in the homolog of a 2-methyl-6-phytyl-1,4-benzoqu

SUBMITTER: Sirikhachornkit A 

PROVIDER: S-EPMC2772410 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature