Abstract: The full length cDNA sequence and genomic DNA（gDNA）sequence of an AP2/EREBP
transcription factor family gene were cloned from Brassica juncea var. tumida Tsen et Lee‘Yong’an’by
RACE（rapid amplification of cDNA ends）and RT-PCR. Amino acid sequence alignment showed the gene
shared 72% similarity with a known Arabidopsis thaliana AP2/EREBP family gene，AtABR1，named after
BjABR1（GenBank accession No. JQ713825.1）. BjABR1 gene contained one intron and putatively encoded
381 amino acids with the protein molecular mass of 41.674 kD，the pI of 9.11，14 phosphorylation sites
and an AP2 DNA-bind domain and a CMX-1 motif. Subcellular localization assays showed that the BjABR1 protein appeared in the nucleus. Quantitative real-time PCR analysis revealed that BjABR1 gene
was expressed in root，stem and leaf，and highest in the root. The expression of BjABR1 was inducible
under salt stress，osmotic stress and cold stress，and its transcriptional responses subject to salinity was
most sensitive.

Key words: BjABR1, Brassica juncea, gene cloning, expression analysis, transcription factor