甘蓝型油菜芸薹素唑耐受因子(BnaBZR1/BnaBES1)全长CDS克隆与生物信息学分析

Cloning and Characterization of Brassinazole-resistant(BnaBZR1 and BnaBES1) CDS from Brassica napus L.

芸薹素唑耐受因子(brassinazole-resistant,BZR)是油菜素内酯信号转导过程中的关键转录因子,目前已知BZR1与BZR2 (BES1)两种亚型。本文在甘蓝型油菜湘油15号cDNA中克隆到3个BZR全长编码序列(coding sequence,CDS),经比对鉴定分别为定位于A07染色体的1拷贝BZR1和定位于A06染色体的2拷贝BES1,分别命名为BnaBZR1_A07、BnaBES1_A06F和BnaBES1_A06R,序列长分别为996、993和996 bp,各自编码331、330、331个氨基酸。这3个基因编码蛋白具有典型植物BZR/BES结构域,亚细胞定位预测主要位于细胞核。多序列比对和进化分析表明, BnaBZR1/BnaBES1基因编码蛋白与甘蓝、白菜、拟南芥、亚麻芥等BZR/BES蛋白具有较高的同源性,且同源物种间BZR1或BES1相似度高于同一物种或者近缘物种中BZR1与BES1间相似度,表明BZR1与BES1分化是一个早期进化事件。湘油15号中这3个基因表达规律相似,苗期和花期具有高水平的BnaBZR基因表达,抽薹期和角果成熟期表达稍低;且BnaBZR基因表达水平在地上部分的叶、茎、花和角果中相对于地下部分的根中较高。

Brassinazole-resistant(BZR)is a key transcription factor in brassinosteroid signaling pathway of plants,containing brassinazole-resistant 1(BZR1)and brassinazole-resistant 2(BES1).In this study,three novel BZR1 coding sequences(CDSs)were isolated from cDNA of Brassica napus L.cv.Xiangyou 15 leaves,which were mapped on the chromosomes A07,A06,and A06,and designated as BnaBZR1_A07,BnaBES1_A06F,and BnaBES1_A06R,respectively.These three BnaBZR CDSs were 996,993,and 996 bp in length and encoded predicted proteins with 331,330,and 331 amino acid residues,respectively.BnaBZR proteins were predicted to be located on the cell nucleus and have a typical plant BZR/BES conserved domain.Multiple sequence alignments and phylogenetic analysis showed that the deduced amino acid sequences of BnaBZR were highly homologous to previously reported BZR/BES of Brassica oleracea,Arabidopsis thalian,and Eruca sativa.And the similarity of BZR1 or BES1 among different related species was higher than the similarity between BZR1 and BES1 in the same species or related species,indicating that BZR1 and BES1 differentiation is an early evolutionary event.The expression patterns of BnaBZR1_A07,Bna-BES1_A06F,and BnaBES1_A06R in Xiangyou 15 were similar,whit high expression level at the seedling stage and flowering stage,while slightly lower level at the stage of bolting and podgrain ripening.The expression level of BnaBZR in the aerial parts such as leaves,stems,flowers and pods was higher than that in underground parts.