African Journal of

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12236

Full Length Research Paper

Cloning and characterization of a nitrite reductase gene related to somatic embryogenesis in Gossypium hirsutum

G. Y. Han#, J. N. Chi#, X. F. Wang, G. Y. Zhang and Z. Y. Ma*
Key Laboratory of Crop Germplasm Resources of Hebei Province, Agricultural University of Hebei, Baoding, 071001, People’s Republic of China.
Email: [email protected]

  •  Accepted: 29 January 2010
  •  Published: 01 March 2010


A nitrite reductase gene related to somatic embryogenesis was first cloned fromGossypium hirsutum. The cDNA sequence of the gene, named GhNiR, is 2,257 bp in length, with 254 bp of the 5’ untranslated region and 236 bp of the 3’ untranslated region. The open reading frame is 1,767 bp in length, encoding a deduced amino acid sequence of 588 residues with a molecular weight of 65.722 kDa and an isoelectric point of 7.07. Semi-quantitative RT-PCR analysis showed that the expression level of GhNiR was higher in embryogenic calli and somatic embryoids than in nonembryogenic calli among different somatic embryogenesis stages, and that the level of GhNiR mRNA was also higher in the cultivar with higher somatic embryogenesis ability. The catalytic GhNiR was verified by transformation in E. coliBL21 (DE3) strain with the recombinant expression vector pET-28A-GhNiR. NiR activity assay showed that the crude GhNiR protein had obvious activity to NaNO2substrate.


Key words: Cotton, nitrite reductase, prokaryotic expression, semi-quantitative RT-PCR, GenBank Accession No: GQ389691.