苎麻CCoAOMT基因cDNA反义转化模式烟草‘WS38’

Transformation of Model Tobacco Variety WS38 with Antisense CCoAOMT cDNA of Boehmeria nivea

苎麻咖啡酰辅酶A氧甲基转移酶(CCoAOMT)是其木质素合成过程的一种关键酶,运用克隆的该酶基因cDNA及植物表达载体pBI121、pWM101,分别构建了35S启动子控制的苎麻CCoAOMT基因反义cDNA基因质粒(pBI121-antiBnCCoAOMT)和cDNA全长表达质粒(pWM101-BnCCoAOMT),并通过根癌农杆菌介导法将其转化至模式烟草WS38,获得了转基因烟草.对转基因植株进行分子分析和组织学初步研究表明,转反义RNA基因植株叶柄木质素含量较野生烟草或转正义基因烟草叶柄木质素含量降低.说明运用反义RNA技术对CCoAOMT基因的表达进行基因工程调控,一定程度上可以对木质素的合成产生干扰,为获得低木质素或木质素组分改良的苎麻基因工程奠定基础.

Caffeoyl-CoA 3-O-methyltransferase is the key enzyme in ramie lignin biosynthesis. The cDNA of ramie CCoAOMT gene was cloned into plant expression vector pBI121 and pWM101 in antisense or sense direction under the control of the 35S promoter. Thus the ramie CCoAOMT antisense gene cDNA expression plasmid （pBI121-antiBnCCoAOMT） and the full length of sense gene CCoAOMT cDNA expression plasmid （pWM101-BnCCoAOMT） were constructed. The recombinants were transformed into Nicotiana tabacurn＇ WS38＇, a model tobacco variety for lignin research, via Agrobacteriurn turnefaciens mediated transformation. Primary histology investigation showed that the lignin in leafstalk of transgenic plantlets is less in content than both the wild tobacco and the sense transformants. The results demonstrated that the antisense RNA of ramie CCoAOMT can take effects on engineering control of lignin synthesis. It clues on lignin genetic engineering method to breed a lower lignin content ramie for better fibre quality.