不结球白菜BrABF1基因的克隆与功能分析

Cloning and Functional Analysis of BrABF1 Gene in Non-Heading Chinese Cabbage

为研究BrABF1基因在不结球白菜中的表达模式并探索其在开花调控中的作用,本研究以不结球白菜苏州青品种为试验材料,通过同源克隆获得BrABF1基因序列,对其氨基酸序列进行比对和进化分析,利用亚细胞定位技术研究BrABF1的空间表达,采用β-D-葡糖醛酸酶(GUS)染色方法研究BrABF1在植物中的表达模式,利用PlantCARE在线软件预测BrABF1基因的启动子的顺式作用元件。构建植物表达载体pEarlyGate101-BrABF1-YFP转化拟南芥,统计野生型和转基因拟南芥植株的开花时间。结果表明,BrABF1基因含有1 104 bp开放阅读框(ORF),编码367个氨基酸。BrABF1与甘蓝型油菜和野甘蓝(原变种)同源性最高,进化关系最近。BrABF1定位在细胞核上。BrABF1启动子驱动的GUS蛋白主要在拟南芥的叶脉中特异性表达。BrABF1启动子序列包含大量的顺式作用元件,如光响应元件、植物激素响应元件、低温响应元件和逆境胁迫响应元件等。转基因拟南芥植株开花时间晚于野生型,表明BrABF1基因能抑制植物的开花。本研究结果为提高不结球白菜商品价值提供了理论基础。

To study the expression pattern of BrABF1 in non-heading Chinese cabbage and explore its role in flowering regulation. The BrABF1 gene sequence was obtained by homologous cloning in non-heading Chinese cabbage Suzhou Qing, and amino acid sequence alignment and evolution analysis were performed. The spatial expression of BrABF1 was studied by subcellular localization technology, and the GUS staining method was used to study the expression pattern of BrABF1 in plants. Moreover, using PlantCARE online software was used to predict the cis-acting element of the promoter of BrABF1. In addition, the plant expression vector pEarlyGate101-BrABF1-YFP was constructed to transform Arabidopsis thaliana. Meanwhile, the flowering time of wild-type and transgenic Arabidopsis plants was compared. The results showed that the BrABF1 gene contains an open reading frame(ORF) of 1104 bp and encodes 367 amino acids. BrABF1 has the closest evolutionary relationship with Brassica napus and Brassica oleracea var. oleracea. BrABF1 is localized in the nucleus. GUS protein driven by the BrABF1 promoter is expressed specifically in the veins of Arabidopsis thaliana. Moreover, the BrABF1 promoter sequence contains a large number of cis-acting elements, including light response elements, plant hormone response elements, low temperature response elements and stress response elements. The flowering time of transgenic Arabidopsis plants were later than that of wild type, which indicate that BrABF1 could inhibit plants flower. The results provide a theoretical basis for improving the commodity value of non-heading cabbage.