Allelic mutant series reveal distinct functions for Arabidopsis cycloartenol synthase 1 in cell viability and plastid biogenesis.

ABSTRACT: Sterols have multiple functions in all eukaryotes. In plants, sterol biosynthesis is initiated by the enzymatic conversion of 2,3-oxidosqualene to cycloartenol. This reaction is catalyzed by cycloartenol synthase 1 (CAS1), which belongs to a family of 13 2,3-oxidosqualene cyclases in Arabidopsis thaliana. To understand the full scope of sterol biological functions in plants, we characterized allelic series of cas1 mutations. Plants carrying the weak mutant allele cas1-1 were viable but developed albino inflorescence shoots because of photooxidation of plastids in stems that contained low amounts of carotenoids and chlorophylls. Consistent with the CAS1 catalyzed reaction, mutant tissues accumulated 2,3-oxidosqualene. This triterpenoid precursor did not increase at the expense of the pathwa

SUBMITTER: Babiychuk E 

PROVIDER: S-EPMC2268602 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature