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期 刊 ：植物遗传资源学报 2015年 16卷 6期

关键词：烟草；BRC1基因；侧枝形成；基因克隆；基因表达分析；

Keywords:tobacco, BRC1 gene, shoot branching, gene cloning, gene expression analysis,

摘 要 ：TCP基因家族CYC/TB1簇中成员BRC1在调控植物侧枝发育的过程中发挥重要作用。本研究利用电子克隆的策略结合RT-PCR方法从普通烟草（Nicotiana tabacum）中克隆到4个NtBRC1-Like基因，分别命名为NtBRC1-Like1、2、3和4。4条基因的CDS序列长度分别为1140、1062、987和1041bp，分别编码由379、353、328和346个氨基酸组成的蛋白，这4个蛋白与CYC/TB1簇中其它成员具有较高同源性。蛋白质保守结构域分析表明，4个NtBRC1-Like基因编码蛋白除具有TCP核心结构域外，还具有CYC/TB1簇蛋白特有的R结构域。系统进化树分析表明，NtBRC1-Like蛋白都是TCP家族CYC/TB1簇中的成员，且4个NtBRC1-Like蛋白可以被分成两组，NtBRC1-Like1和4为一组，NtBRC1-Like2和3为另一组。荧光定量PCR分析发现，4条烟草NtBRC1-Like基因的表达呈现明显的组织特异性，且其表达模式可分为两种：NtBRC1-Like1和4的表达模式相似，在腋芽中有极高的表达；NtBRC1-Like2和3的表达模式十分相像，在叶和腋芽中的表达量都显著高于其它组织。推测烟草BRC1基因可能存在类似番茄BRC1基因在功能上保守与进化的情况。

Abstract:The members of CYC/TB1 subclass in TCP gene family play an important role in the regulation of shoot branching. Four new NtBRC1-Like genes, designated NtBRC1-Like1, 2, 3 and 4, were isolated from Nicotiana tabacum using silico cloning strategy combined RT-PCR methods. The length of CDS sequences of four NtBRC1-Like genes were 1140, 1062, 987 and 1041 bp, respectively. The deduced protein sequences contained 379, 353, 328 and 346 amino acids, respectively, and exhibited high homology with other members of CYC/TB1 subclass. The analysis of conserved domain showed that, in addition to the TCP core domain, four NtBRC1-Like proteins also had the R domain specific to CYC/TB1 proteins. The phylogenetic tree showed that four NtBRC1-Like proteins belonged to CYC/TB1 subclass of TCP family, however, four NtBRC1-Like proteins could be divided into two groups, one is NtBRC1-Like1/4，another is NtBRC1-Like2/3. Real-time quantitative PCR assay indicated that the expression profile of NtBRC1-Like genes exhibited significant tissue specificity. The expression level of NtBRC1-Like1/4 in axillary bud was the highest, however, NtBRC1-Like2/3 expressed higher in leaf and axillary bud. These results demonstrated that the functions of NtBRC1s in tobacco might be differentiated just like in tomato.

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