关键词: 光皮桦, Betula luminifera, BlCOL13, BBX, 基因克隆, 表达分析

Abstract: The full-length cDNA，genomic DNA and promoter sequence of BlCOL13 were cloned from Betula luminifera with RACE，RT-PCR and Genome Walking methods respectively. BlCOL13 genomic DNA was 2 808 bp containing 4 exons and 3 introns，and its cDNA was 1 370 bp encoding a protein of 379 amin acids. The BlCOL13 protein contained 2 B-box domains at N terminus and 1 CCT domains at C terminus which was classified into BBX proteins. Basing on the classification rules of BBX in Arabidopsis，BlCOL13 belongs to type Ⅱ BBX. There are several cis-elements related with flowering，light-response，hormone signal transduction and stress response in the promoter of BlCOL13 which was 685 bp. Nuclear localization with BlCOL13 merged protein with GFP implied BlCOL13 mainly located in the nucleus. BlCOL13 all expressed in roots stems，leaves，male and female flowers，but highly in male flowers. qRT-PCR result of BlCOL13 under low temperature，drought，ABA and salt treatments revealed it was induced by these abiotic stress condition，especially for the salt treatment，implying BlCOL13 possiblyplayed important roles in stress resistance in Betula luminifera.

Key words: Betula luminifera, BlCOL13, BBX, gene clone, gene express