Abstract: A new cDNA BnHMGB2 was isolated from Brassica napus long you6 by RACE. The cloned full-length cDNA was 823 bp, contained a 438 bp ORF, a 5′untranslated region (5-UTR) of 131 bp, and a 3′untranslated region (3′UTR) of 253 bp. The nucleotide sequence of BnHMGB2 was 87.4% identical with the Arabidopsis thaliana AtHMGB2, so it was named BnHMGB2(GenBank accession: JN807314). BnHMGB2 encoded a protein of 145 amino acids with a deduced molecular weight of about 15.9 KDa and with a PI of 5.63. Analysis by real-time RT-PCR indicated that BnHMGB2 was expressed in root, stem, leaf and hypocotyl of B.napus and relatively higher abundance was observed in root tissue. Sequence analysis indicated that the BnMKK2 protein exhibited closest homology to MAPKK which is responded to cold stress, and BnHMGB2 played an important role in defending cold stress.

Key words: longyou 6, BnHMGB2 gene, gene cloning, expression analysis