title: Isolation and characterization of a lycopene ε-cyclase gene of Chlorella (Chromochloris) zofingiensis. Regulation of the carotenogenic pathway by nitrogen and light.
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.
authors.affiliation: Institute of Plant Biochemistry and Photosynthesis, CIC Cartuja, University of Seville and CSIC, Avda. Americo Vespucio, n° 49, Seville 41092, Spain.
authors.forename: Baldo F
authors.initials: BF
authors.lastname: Cordero
authors.affiliation: Institute of Plant Biochemistry and Photosynthesis, CIC Cartuja, University of Seville and CSIC, Avda. Americo Vespucio, n° 49, Seville 41092, Spain.
authors.forename: Inmaculada
authors.identifier: 0000-0003-2849-675X
authors.initials: I
authors.lastname: Couso
authors.affiliation: Department of Chemistry, Experimental Sciences Faculty, University of Huelva, Avda. Fuerzas Armadas s/n, Huelva 27071, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Leon
authors.affiliation: Institute of Plant Biochemistry and Photosynthesis, CIC Cartuja, University of Seville and CSIC, Avda. Americo Vespucio, n° 49, Seville 41092, Spain.
authors.forename: Herminia
authors.initials: H
authors.lastname: Rodriguez
authors.affiliation: Institute of Plant Biochemistry and Photosynthesis, CIC Cartuja, University of Seville and CSIC, Avda. Americo Vespucio, n° 49, Seville 41092, Spain.
authors.forename: Maria Angeles
authors.initials: MA
authors.lastname: Vargas
mesh_terms: D016644:Canthaxanthin / Q000096:biosynthesis; D002338:Carotenoids / Q000096:biosynthesis; D002708:Chlorella / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D019753:Intramolecular Lyases / Q000235:genetics*; D008027:Light; D014975:Lutein / Q000096:biosynthesis; D058086:Microalgae / Q000187:drug effects / Q000235:genetics*; D009584:Nitrogen / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics; D024341:Xanthophylls / Q000096:biosynthesis; D065146:Zeaxanthins; D019207:beta Carotene / Q000096:biosynthesis
chemical_list: D012333:RNA, Messenger; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; C041635:alpha-carotene; D016644:Canthaxanthin; C005613:violaxanthin; C005948:astaxanthine; D019753:Intramolecular Lyases; C070925:lycopene cyclase-isomerase; D009584:Nitrogen; D014975:Lutein
keywords: carotenoids; gene expression; gene regulation; lycopene cyclase genes; microalgae