论文部分内容阅读
在香蕉基因组中寻找具有抗倒伏功能的基因,为培育抗倒伏香蕉新品种奠定基础。香豆酸:Co A连接酶(4CL)是植物木质素合成的限速酶。香蕉A基因组中有25个4CL基因同源序列。高粱基因bmr2是一个已经被鉴定的具有4CL功能的基因。与bmr2进行序列比对,将候选基因在大肠杆菌中过量表达,提取重组蛋白,研究其催化活性。将候选基因在烟草中过量表达,研究转基因植株与对照的木质素含量和茎秆物理强度。香蕉4-香豆酸:Co A连接酶基因Mu4CL15预测的底物结合域序列、二级结构、三级结构都与bmr2的相应序列具有高度的相似性。将Mu4CL15在大肠杆菌中表达并提取纯化,重组蛋白质催化效率最高的底物是4-香豆酸,其次是咖啡酸、阿魏酸和芥子酸。将Mu4CL15在烟草中进行转化后发现,转基因植株茎秆的木质素含量显著高于只转化空载体的野生型。转基因幼苗的茎秆强度显著高于只转化空载体的野生型。在烟草中过量表达Mu4CL15能够增加烟草植株茎秆的木质素含量和抗倒伏能力。通过过量表达基因Mu4CL15极有可能能够提高香蕉植株假茎的抗倒伏能力。
Looking for a gene with lodging resistance in the genome of banana, which lays the foundation for cultivating lodging banana new varieties. Coumarate: Co A ligase (4CL) is the rate-limiting enzyme in plant lignin synthesis. There are 25 4CL gene homologous sequences in banana A genome. The sorghum gene bmr2 is a 4CL-functional gene that has been identified. And bmr2 sequence alignment, the candidate gene in E. coli overexpression, the recombinant protein was extracted to study its catalytic activity. Candidate genes were overexpressed in tobacco to study lignin content and stalk physical strength of transgenic plants and controls. Banana 4-coumarate: Co A ligase gene Mu4CL15 predicted substrate binding domain sequence, secondary structure, tertiary structure and bmr2 corresponding sequence has a high degree of similarity. Mu4CL15 was expressed in Escherichia coli and extracted and purified. The most catalytically efficient substrate for the recombinant protein was 4-coumarate, followed by caffeic acid, ferulic acid and sinapic acid. Transformation of Mu4CL15 in tobacco revealed that the lignin content of the stalk of the transgenic plants was significantly higher than that of the wild type that transformed empty vector only. The stalk strength of transgenic seedlings was significantly higher than that of wild-type, which only transformed empty vector. Overexpression of Mu4CL15 in tobacco increased the lignin content and lodging resistance of tobacco plant stalks. By overexpressing the gene Mu4CL15, it is highly possible to increase the lodging resistance of the banana plant pseudostem.