Authors: Duc Tran James Haven WeiGang Qiu Juergen E W Polle
Publish Date: 2008/12/09
Volume: 229, Issue: 3, Pages: 723-729
Abstract
Carotenoids play crucial roles in structure and function of the photosynthetic apparatus of bacteria algae and higher plants The entrystep reaction to carotenoid biosynthesis is catalyzed by the phytoene synthase PSY which is structurally and functionally related in all organisms A comparative genomic analysis regarding the PSY revealed that the green algae Ostreococcus and Micromonas possess two orthologous copies of the PSY genes indicating an ancient gene duplication event that produced two classes of PSY in algae However some other green algae Chlamydomonas reinhardtii Chlorella vulgaris and Volvox carteri red algae Cyanidioschyzon merolae diatoms Thalassiosira pseudonana and Phaeodactylum tricornutum and higher plants retained only one class of the PSY gene whereas the other gene copy was lost in these species Further similar to the situation in higher plants recent gene duplications of PSY have occurred for example in the green alga Dunaliella salina/bardawil As members of the PSY gene families in some higher plants are differentially regulated during development or stress the discovery of two classes of PSY gene families in some algae suggests that carotenoid biosynthesis in these algae is differentially regulated in response to development and environmental stress as well
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