香蕉4-CL基因Mu4CL15的功能鉴定

发布时间：2019-05-18 22:19

【摘要】：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。
[Abstract]:To find genes with lodging resistance in banana genome, which laid a foundation for the cultivation of new lodging resistant banana varieties. Coumaric acid: Co A ligase (4CL) is a rate-limiting enzyme for plant lignin synthesis. There are 25 homologous sequences of 4CL gene in banana A genome. Sorghum gene bmr2 is a gene with 4CL function that has been identified. Compared with bmr2, the candidate genes were overexpressed in E. coli, the recombinant protein was extracted, and its catalytic activity was studied. The lignin content and stem physical strength of transgenic plants and controls were studied by overexpression of candidate genes in tobacco. The substrate binding domain sequence, secondary structure and tertiary structure predicted by banana 4-coumaric acid: Co A ligase gene Mu4CL15 are highly similar to the corresponding sequences of bmr2. Mu4CL15 was expressed in E. coli and purified. The substrate with the highest catalytic efficiency of recombinant protein was 4-coumaric acid, followed by caffeine, ferulic acid and erucic acid. After transformation of Mu4CL15 in tobacco, it was found that the lignin content of the stem of the transgenic plant was significantly higher than that of the wild type only transformed with empty carrier. The stem strength of transgenic seedlings was significantly higher than that of wild type only transformed into empty carrier. Overexpression of Mu4CL15 in tobacco could increase lignin content and lodging resistance of tobacco stems. Overexpression of gene Mu4CL15 is likely to improve the lodging resistance of false stems of banana plants.
【作者单位】：中国热带农业科学院海口实验站;海南省香蕉遗传改良重点实验室;海南大学农学院;
【基金】：海南省重点研发项目(No.ZDYF2016069) 国家自然科学基金(No.31371696) 农业部948项目(No.2015-Z21)共同资助
【分类号】：Q943.2;S668.1

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