Cloning And Function Analysis Of SUR1 Gene From Broccoli (Brassica Oleracea Var.Italica)

Broccoli(Brassica oleracea var. Italica), also called cauliflower, green cauliflower, is an important crop cruciferous(Brassicaceae) Brassica(Brassica) plant, widely been planted in our country. Broccoli originated from Italy, spreaded to our country in late 19 th and early 20 th century,is known as "vegetable crown", its buds and stems have a wealth of nutrients, such as protein,carotene, vitamins and minerals.However, the scientists most interested is its excellent anti-cancer effect, studies have shown that regular consumption of broccoli can reduce the risk of suffering from a variety of tumor diseases, such as pancreatic cancer, ovarian cancer, breast cancer, colorectal cancer and gastric cancer, etc. The substances have the anticancer activity present in broccoli is isothiocyanate, the hydrolysis product of secondary metabolites called glucosinolate. Therefore, study the metabolism in broccoli is significantly important.In this study, broccoli as experimental materials, refered to previous work about transcriptome sequencing results, cloned the full-length mRNA of the SUR1 gene involved in biosynthesis of glucosinolate in broccoli by RACE method. Verified the gene function according to the main phenotypes of transgenic Arabidopsis overexpressed the broccoli SUR1 gene and named it as Bo SUR1. This study provided a theoretical reference and genetic resources for further explore about glucosinolates metabolism in broccoli and genetic engineering methods to cultivate varieties of broccoli contain a high content of glucosinolates and anti-cancer activity.The main results of this paper:Cloned the full-length mRNA sequence of Bo SUR1. The CDS sequence length of Bo SUR1 gene is 1371 bp, encoding a protein containing 456 amino acid residues, molecular weight50.45 KD. BLAST results showed that: the gene has 98% homology with Brassica rapa subsp.rapa cultivar(EF611275.1, EF611274.1, EF611276.1, EF611273.1), Brassica rapa subsp.rapa cultivar Yorii Spring(EF611272.1), Brassica rapa subsp. pekinensis cultivar Matsushima(EF611271.1),Brassica rapa subsp. Pekinensis(FJ376052.1) and Brassica rapa subsp.chinensis(EF611278.1);has 94% homology with Eruca vesicaria subsp. Sativa(JX946194.1); has a 88% homology with Arabidopsis.Constructed the transgenic Arabidopsis overexpressing Bo SUR1 gene successfully, laid the material foundation for verifying and studying the function of Bo SUR1 gene in depth.Phenotypic analysis of 35S::Bo SUR1 transgenic Arabidopsis show that the content of aliphatic glucosinolates and indole glucosinolate increased significantly, verified Bo SUR1 gene had the expected activity to catalyze the synthesis of glucosinolates.The significance of this study: cloning and verifying of Bo SUR1 gene laid the foundation for further research on synthesis or metabolism in broccoli and cultivate the new varieties of broccoli contain a high content of glucosinolates.