Isolation and Characterization of a Lycopene ε-Cyclase Gene of Chlorella Chromochloris zofingiensis. Regulation of the Carotenogenic Pathway by Nitrogen and LightReportar como inadecuado




Isolation and Characterization of a Lycopene ε-Cyclase Gene of Chlorella Chromochloris zofingiensis. Regulation of the Carotenogenic Pathway by Nitrogen and Light - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

1

Institute of Plant Biochemistry and Photosynthesis, CIC Cartuja, University of Seville and CSIC, Avda. Americo Vespucio, n° 49, Seville 41092, Spain

2

Department of Chemistry, Experimental Sciences Faculty, University of Huelva, Avda. Fuerzas Armadas s-n, Huelva 27071, Spain





*

Author to whom correspondence should be addressed.



Abstract The isolation and characterization of the lycopene ε-cyclase gene from the green microalga Chlorella Chromochloris zofingiensis Czlcy-e was performed. This gene is involved in the formation of the carotenoids α-carotene and lutein. Czlcy-e gene encoded a polypeptide of 654 amino acids. A single copy of Czlcy-e was found in C. zofingiensis. Functional analysis by heterologous complementation in Escherichia coli showed the ability of this protein to convert lycopene to δ-carotene. In addition, the regulation of the carotenogenic pathway by light and nitrogen was also studied in C. zofingiensis. High irradiance stress did not increase mRNA levels of neither lycopene β-cyclase gene lcy-b nor lycopene ε-cyclase gene lcy-e as compared with low irradiance conditions, whereas the transcript levels of psy, pds, chyB and bkt genes were enhanced, nevertheless triggering the synthesis of the secondary carotenoids astaxanthin, canthaxanthin and zeaxanthin and decreasing the levels of the primary carotenoids α-carotene, lutein, violaxanthin and β-carotene. Nitrogen starvation per se enhanced mRNA levels of all genes considered, except lcy-e and pds, but did not trigger the synthesis of astaxanthin, canthaxanthin nor zeaxanthin. The combined effect of both high light and nitrogen starvation stresses enhanced significantly the accumulation of these carotenoids as well as the transcript levels of bkt gene, as compared with the effect of only high irradiance stress. View Full-Text

Keywords: carotenoids; microalgae; lycopene cyclase genes; gene expression; gene regulation carotenoids; microalgae; lycopene cyclase genes; gene expression; gene regulation





Autor: Baldo F. Cordero 1, Inmaculada Couso 1, Rosa Leon 2, Herminia Rodriguez 1,* and Maria Angeles Vargas 1

Fuente: http://mdpi.com/



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