title: Expression of bkt and bch genes from Haematococcus pluvialis in transgenic Chlamydomonas.
abstract: β-carotene ketolase and β-carotene hydroxylase encoded by bkt and bch, respectively, are key enzymes required for astaxanthin biosynthesis in Haematococcu pluvialis 34-1n. Two expression vectors containing cDNA sequences of bkt and bch were constructed and co-transformed into cell-wall-deficient Chlamydomonas reinhardtii CC-849. Transgenic algae were screened on TAP agar plates containing 10 μg mL(-1) Zeomycin. PCR-Southern analysis showed that bkt and bch were integrated into the genomes of C. reinhardtii. Transcripts of bkt and bch were further confirmed by RT-PCR-Southern analysis. Compared with the wild type, transgenic algae produced 29.04% and 30.27% more carotenoids and xanthophylls, respectively. Moreover, the transgenic algae could accumulate 34% more astaxanthin than wild type. These results indicate that foreign bkt and bch genes were successfully translated into β-carotene ketolase and β-carotene hydroxylase, which were responsible for catalyzing the biosynthesis of astaxanthin in transgenic algae.
authors.affiliation: Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Science, Shenzhen University, Shenzhen, 518060, China.
authors.forename: KaiJing
authors.initials: K
authors.lastname: Zheng
authors.forename: ChaoGang
authors.initials: C
authors.lastname: Wang
authors.forename: Ming
authors.initials: M
authors.lastname: Xiao
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: JianCheng
authors.initials: J
authors.lastname: Li
authors.forename: ZhangLi
authors.initials: Z
authors.lastname: Hu
mesh_terms: D020418:Algal Proteins / Q000235:genetics / Q000378:metabolism*; D002338:Carotenoids / Q000737:chemistry; D002467:Cell Nucleus / Q000378:metabolism; D002473:Cell Wall; D002696:Chlamydomonas / Q000235:genetics*; D000460:Chlorophyta / Q000201:enzymology* / Q000235:genetics; D018076:DNA, Complementary; D005821:Genetic Techniques; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism*; D019076:Transgenes; D024341:Xanthophylls / Q000737:chemistry
chemical_list: D020418:Algal Proteins; D018076:DNA, Complementary; D024341:Xanthophylls; D002338:Carotenoids; C005948:astaxanthine; D006899:Mixed Function Oxygenases; D010105:Oxygenases; C093259:beta-carotene ketolase; C079232:beta-carotene hydroxylase