Abstract: A pair of primers was designed according to the sequence of nitrate reductase gene in GenBank (gb∣ABW05098.1∣). The homolog cDNA with 2 760 base pairs of nitrate reductase gene was obtained by RT-PCR from total RNA using Beta vulgaris treated by 50 mmol·L^-1 KNO₃ as material. DNA sequence analysis showed that it contains the entire open reading frames that encode deduced protein with 905 amino acid residues and shows 99% sequence identity to B. vulgaris nitrate reductase gene. Southern hybridization experiments revealed that nitrate reductase gene might be exist as two copy or low copy in the genome of B. vulgaris. According to the amino acid sequences, the subcellular location and structure of the nitrate reductase were predicted.

Key words: Beta vulgaris, nitrate reductase, Gene cloning, RT-PCR