Isolation and characterization of a stress-inducible Dunaliella salina Lcy-β gene encoding a functional lycopene β-cyclase

The halotolerant green alga Dunaliella salina accumulates large amounts of β-carotene when exposed to various stress conditions. Although several studies concerning accumulation and biotechnological production of β-carotene have been published, the molecular basis and regulation of the genes involved in carotenoid biosynthesis in D. salina are still poorly known. In this paper, we report the isolation and regulation of the lycopene β-cyclase (Lcy-β) gene by abiotic stress. The function of this gene was determined by heterologous genetic complementation in E. coli. Gene expression and physiological analyses revealed that D. salina Lcy-β steady-state transcript and carotenoid levels were up-regulated in response to all stress conditions tested (salt, light and nutrient depletion). The results presented here suggest that nutrient availability is a key factor influencing carotenogenesis as well as carotenoid biosynthesis-related gene expression in D. salina.

Keywords

Carotenoid biosynthesis Dunaliella salina Lycopene β-cyclase Gene expression Stress response regulation

URI

http://hdl.handle.net/10400.1/4838

Citation

Ramos, A., S. Coesel, A. Marques, M. Rodrigues, A. Baumgartner, J. Noronha, A. Rauter, B. Brenig & J. Varela (2008). Isolation and characterization of a stress-inducible Dunaliella salina Lcy-β gene encoding a functional lycopene beta-cyclase. Applied Microbiology and Biotechnology, 79: 819-828.