三角梅cDOPA 5GT基因的克隆和光照对其表达的影响

Cloning of Cyclo-DOPA-5-glucosyltransferase Gene from Bougainvillea glabra and Effect of Illumination on Its Expression

摘要:

为了解光照对三角梅（Bougainvillea glabra）葡糖基转移酶基因表达的影响，从其苞片中克隆了环多巴5-糖基转移酶基因（cDOPA 5GT）。结果表明，三角梅cDOPA 5GT基因的cDNA全长为1 446 bp，编码482个氨基酸，生物信息学分析表明cDOPA 5GT蛋白的等电点（PI）为5.77，具有糖基转移酶的特征基序，为酸性亲水跨膜蛋白，不含信号肽，二级结构以α-螺旋和无规则卷曲为主，氨基酸序列保守性较差。qRT-PCR分析表明，遮光处理cDOPA 5GT基因表达量和植株的甜菜红素含量均显著下降。这表明三角梅的色素合成受糖基转移酶基因调控，并与光照呈正相关关系。

Abstract:

In order to understand the effect of illumination on the expression of glucosyltransferase gene in Bougainvillea glabra, the cyclo-DOPA-5-glucosyltransferase gene (cDOPA 5GT) was cloned from bracts. The results showed that the full length cDNA of cDOPA 5GT was 1 446 bp, encoding 482 amino acids. The bioin-formatics analysis showed that isoelectric point of cDOPA 5GT was 5.77, showing an acidic and hydrophilic transmembrane protein without signal peptide. The cDOPA 5GT protein had characteristic motifs of glucosyl-transferase, and the secondary structure was dominant of α-helices and random coils, and the amino acid sequence was less conserved. The results of qRT-PCR and spectrophotometry showed that the expression of cDOPA 5GT gene and betacyanin accumulation in plants decreased significantly under shading by qRT-PCR and spectro-photometry. Therefore, it was suggested that the synthesis of betacyanin was regulated by glucosyltransferase gene, and positively correlated with light time.