油菜BnHMGB2基因的克隆及表达分析

通过RACE技术从陇油6号油菜中克隆得到了一种新的BnHMGB2基因的cDNA，全长823 bp,其中包括438 bp的开放阅读框，131 bp的5′非翻译区（5′UTR），253 bp的3′非翻译区（3′UTR）。与拟南芥AtHMGB2的同源性达到了87.4%，因此命名为BnHMGB2(GenBank登录号：JN807314)。该基因编码145个氨基酸的蛋白质，分子量15.9 KDa，等电点为5.63。实时荧光定量PCR结果表明该基因在油菜根、茎、叶、下胚轴均有表达，根中表达量最高。同时，该基因的表达受低温胁迫的诱导，表明该基因在油菜适应低温胁迫的过程中发挥作用。

Cloning and Expression Analysis of BnHMGB2 Gene in Brassica napus

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.