甘蓝型油菜BnXTH1基因的克隆与表达分析

Cloning and Expression Analysis of BnXTH1 Gene from Brasscia napus

木葡聚糖内糖基转移酶/水解酶(XTH)是一类庞大的多基因家族,在细胞壁形成以及植物生长发育过程中起重要作用。本研究利用同源序列设计引物进行PCR扩增,克隆得到甘蓝型油菜XTH基因的cDNA序列,将其命名为BnXTH1(GenBank登录号:KF612342)。BnXTH1的开放阅读框长855 bp,编码284个氨基酸,预测的蛋白质相对分子质量为32.46 kD,等电点为8.84,含有典型的XTH蛋白催化活性序列DEIDFEFLGN。系统进化分析表明该基因与拟南芥XTH17进化关系最近。半定量RT-PCR分析结果显示,BnXTH1在花和根中表达量较高,其在幼苗中的表达受赤霉素、油菜素内酯以及生长素的诱导,推测该基因可能与幼苗生长发育的调控有关。

Xyloglucan endotransglucosylase/hydrolase （XTH） is a large multigene family. XTHs play an essential role in the formation of cell wall and plant growth and development. Based on the homologous sequence, a eDNA fragment of XTH gene was cloned in Brass i ca nap us, designated as BnXTH1 （GenBank accession No. KF612342）. The complete open reading frame of BnXTH1 is 855bp in length, encoding 284 amino acid residues. The deduced BnXTH1 protein contains the typical XTHs catalytic active site sequence DEIDFEFLGN, with a predicted molecular mass of 32.46 kD and a pI of 8.84. Phylogenetic analysis revealed that the deuced protein was closest to the XTH17 protein in Arabidopsis. Semi-quantitative RT-PCR with gene specific primers showed that BnXTH1 was highly expressed in roots and flowers, and its expression in young seedlings was induced by GA, BR and IAA treatment. This result suggested that BnXTH1 may involved in the regulation of growth and development of young seedlings.