Intragenic enhancers and suppressors of phytoene desaturase mutations in Chlamydomonas reinhardtii.

ABSTRACT: Photosynthetic organisms synthesize carotenoids for harvesting light energy, photoprotection, and maintaining the structure and function of photosynthetic membranes. A light-sensitive, phytoene-accumulating mutant, pds1-1, was isolated in Chlamydomonas reinhardtii and found to be genetically linked to the phytoene desaturase (PDS) gene. PDS catalyzes the second step in carotenoid biosynthesis--the conversion of phytoene to ζ-carotene. Decreased accumulation of downstream colored carotenoids suggested that the pds1-1 mutant is leaky for PDS activity. A screen for enhancers of the pds1-1 mutation yielded the pds1-2 allele, which completely lacks PDS activity. A second independent null mutant (pds1-3) was identified using DNA insertional mutagenesis. Both null mutants accumulate only phytoene

SUBMITTER: Tran PT 

PROVIDER: S-EPMC3419514 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature