ACA基因启动子的克隆及功能初探

根据已知的ACA基因的5’端序列设计三个基因特异的反向引物(GSP-1，GSP-2，GSP-3)分别与11个简并引物(AD1-AD11)配对，进行热不对称嵌套PCR(Thermal asymmetric interlaced PCR，TAIL-PCR)扩增，获得了ACA基因起始密码子上游约700bp的片段。为检测其表达特性，构建了该片段与Gus嵌合基因的表达载体pBpAG，在真空条件下通过农杆菌介导，转化了植物的叶、果实、种子三种不同组织，Gus瞬时表达染色结果显示，该DNA片段具有种子特异的启动子活性?对该启动子的一些顺式元件进行了讨论。

Cloning of ACA Gene Promoter and Preliminary Study of its Function

Using total DNA isolated from Amaranthus caudatus as the template, a DNA fragment of about 700bp upstream of the coding sequence of Amaranthus caudatus agglutinin(ACA) gene was amplified by TAIL_PCR and cloned. To examine the regulatory function of this DNA fragment, it was inserted into a plant expression vector containing GUS gene to substitute the CaMV 35S promoter and the resulted recombinant plasmid was designated as pBpAG. The expression vector pBpAG was transferred to different tissues of plants, via Agrobacterium _mediated transformation in vacuum condition. Transient expression of GUS in the transformed tissues was detected by histochemical GUS staining and the results showed that the GUS activity was expressed specifically in seeds.These preliminary results indicate that this DNA fragment upstream of the ACA coding sequence could very possibly be a promoter with seed specificity. Some putative cis_elements within the promoter were discussed.