生长素合成关键酶基因iaaM种子特异表达载体的构建及转基因油菜的获得

Construction of Seed-specific Expression Vector of Auxin Synthesis Gene iaaM and Regeneration of Transgenic Brassica napus L.

生长素是重要的植物激素,它对植物的生长发育具有重要的调控作用,它能诱导营养物质向其含量高的部位运输。通过转基因技术提高内源生长素在油菜种子中的含量,诱导营养物质向种子运输,为提高油菜灌浆速度,增加产量提供了新的研究方向。iaaM基因编码的色氨酸单加氧酶是催化色氨酸(Trp)转变为生长素(IAA)的关键酶,将iaaM基因与油菜(Brassica napusL.)种子发育早期特异性表达的储藏蛋白专一性启动子(Napin)融合并插入植物表达载体pCAMBIA3301中,构建iaaM基因的种子特异表达载体,并经农杆菌介导转化甘蓝型油菜。经PPT抗性筛选、GUS组织化学检测、PCR检测,初步证实外源基因已整合进油菜基因组,获得转基因植株。

Auxin is an important phytohormone in the regulation of plant growth and development by inducing the nutrients to the site where the content auxin is higher. Increasing the auxin content in rapeseed through genetic transformation can induce nutrients transport to seeds, prevent the flower wilting and silique withered,increase the silique number, and thus increasing the yield of rapeseed. Tryptophan monooxygenase encoded by iaaM gene is the key enzyme in converting tryptophane to indole-3-acetic acid. In order to study the effect of auxin in developing seed, we constructed a plant expression vector carrying auxin synthesis gene iaaM coding sequence under the control of the seed-specific napin promoter from Brassica napus L. , and it was introduced into B. napus L. mediated by Agrobacterium tumefaciens LBA4404. Some PPT - resistant green shoots were obtained. The results of GUS assay and PCR amplification indicated that the foreign gene was stably integrated and expressed in the genome of rapeseed.