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.
Copyright © 2019 Author(s) retain the copyright of this article.
This article is published under the terms of the Creative Commons Attribution License 4.0