title: Cloning and transcription analysis of the nitrate reductase gene from Haematococcus pluvialis.
abstract: OBJECTIVE
  To optimize the cultivation media for the growth rate of Haematococcus pluvialis and to study the transcription regulation of the algal nitrate reductase (NR), a key enzyme for nitrogen metabolism.
  
  
  RESULTS
  The NR gene from H. pluvialis hd7 consists of 5636 nucleotides, including 14 introns. The cDNA ORF is 2718 bp, encoding a 905 aa protein with three conserved domains. The NR amino acids of H. pluvialis hd7 are hydrophilic and have similarity of 72% compared to that of Dunaliella. NR transcription increased with an increase of nitrate concentration from 0.4 to 1 g/l. A deficiency of nitrogen increased NR transcription significantly. The transcription level of NR increased at phosphorus concentrations from 0.08 to 0.2 g/l, with a maximum at 0.08 g/l. The optimum parameters of medium component for transcription of NR and growth of H. pluvialis were 0.3 g NaNO3/l, 0.045 g KH2PO4/l and 1.08 g sodium acetate/l.
  
  
  CONCLUSIONS
  This study provides a better understanding of nitrate regulation in H. pluvialis.
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao, 266003, People's Republic of China.
authors.forename: Lu-Lu
authors.initials: LL
authors.lastname: Hou
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao, 266003, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao, 266003, People's Republic of China. xnzang@ouc.edu.cn.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Zang
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao, 266003, People's Republic of China.
authors.forename: Xuecheng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao, 266003, People's Republic of China.
authors.forename: Bangxiang
authors.initials: B
authors.lastname: He
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao, 266003, People's Republic of China.
authors.forename: Yating
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao, 266003, People's Republic of China.
authors.forename: Xinwei
authors.initials: X
authors.lastname: Song
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao, 266003, People's Republic of China.
authors.forename: Dongfang
authors.initials: D
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao, 266003, People's Republic of China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Wang
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D020418:Algal Proteins / Q000235:genetics*; D000595:Amino Acid Sequence; D018929:Cell Culture Techniques; D000460:Chlorophyta / Q000201:enzymology* / Q000235:genetics; D048028:DNA, Algal / Q000235:genetics; D015870:Gene Expression; D050901:Nitrate Reductase / Q000235:genetics*; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D020418:Algal Proteins; D048028:DNA, Algal; D009566:Nitrates; D010758:Phosphorus; D050901:Nitrate Reductase; D009584:Nitrogen; D019342:Acetic Acid
keywords: Astaxanthin; Haematococcus pluvialis; Nitrate reductase; Nitrogen metabolism