苹果矮化砧木T337 MdCBB1基因的克隆与表达分析

Cloning and Expression Analysis of MdCBB1 Genes in Apple Rootstock T337

为研究油菜素内酯(BR)对苹果矮化砧木T337株高调控机制的影响,以T337盆栽苗为试材,利用RT-PCR技术从T337中分离出BR合成关键基因MdCBB1.1和MdCBB1.2,二者的开放阅读框均为1 707bp,分别编码一个568个氨基酸的蛋白,分子质量分别为6.624 1×104 ku和6.622 8×104 ku。生物信息学分析结果显示,MdCBB1.1和MdCBB1.2基因编码的蛋白含有FAD_binding_4和GlcD 2个明显的结构域,为非核蛋白,属于植物CBB1蛋白家族。表达分析结果显示,MdCBB1.1和MdCBB1.2基因在T337不同组织均有表达,但是顶梢和根中的表达量明显高于其他组织(P<0.05)。并且外源芸苔素内酯(BL)处理能够上调二者在木质部中的表达(P<0.05)。

To investigate the mechanism of brassinolide （BR） affecting the height of apple dwarf root- stock T337, T337 seedlings were used for research. Full-length MdCBB1. I and MdCBB1. 2 genes were isolated from T337 by using RT-PCR technology. Both MdCBB1. I and MdCBB1.2 , playing a key role in BR biosynthesis, comprises a 1 707 bp open reading frame, encoding a 568 amino acids pro- tein with the molecular mass of 6. 624 1 X 10^4 ku and 6. 622 8 X 10^4 ku, respectively. Bioinformatics analysis revealed that the predicted protein is not nucleoprotein and including the typical sequences of CBB1 family, the FAD_binding_4 and GlcD domain. The expression analysis indicated that bothMd- CBB1. I andMdCBB1.2 genes expressed in different tissues of T337, hut the expression amount dif- fered significantly （P〈0.05）. The higher level of the expression was detected in shoot tip and root. Moreover, in xylem, the transcript level ofMdCBB1.1 andMdCBB1.2 were increased by the exoge- nous BL （P〈0.05）.