The responses of two genes encoding phytoene synthase (Psy) and phytoene desaturase (Pds) to nitrogen limitation and salinity up-shock with special emphasis on carotenogenesis in Dunaliella parva

Green alga Dunaliella parva can adapt to environmental stresses such as salinity up-shock and nitrogen limitation which are associated with carotenoid accumulation. However, the underlying molecular basis related to the change of carotenoid content needs further study. In the present study, we cloned two carotenoid biosynthesis genes coding for phytoene synthase and phytoene desaturase. In addition, the effects of salinity up-shock and nitrogen limitation on carotenoid content and expression of these two genes were studied in D. parva FACHB-815. The results showed that both salinity up-shock and nitrogen limitation had important effect on carotenoid yield and expression of these two genes. Cloning and expression analysis of these two genes will contribute to the understanding of molecular basis in stress-induced carotenoid accumulation, which is favorable for performing metabolic and genetic engineering to improve traits of D. parva.