摘要: 该研究为了培育兼抗4种病毒的马铃薯品种,采用RTPCR技术对PVX、PVS、PVY和PLRV的外壳蛋白(CP)基因进行克隆与分析,获得了大小分别为670、800、700、600 bp的CP基因序列,将获得的CP基因序列与NCBI中已报道的序列进行比对分析,其同源性都在96%以上。根据所克隆的CP基因对靶标片段进行筛选,获得了大小约300 bp的靶标片段PVXrh、PVSrh、PVYrh和PLRVrh,同时利用 OverlapPCR技术将4种病毒的靶标片段进行拼接,得到了长度约为1 200 bp的融合片段XSYVrh,与预期目标片段XSYVyxz的相似性达100%。利用DNA重组技术将融合片段XSYVrh克隆到pGMT载体上构建成克隆载体pGMTXSYVrh,用SpeⅠ和SacⅠ对克隆载体pGMTXSYVrh和植物表达载体pART27进行同步双酶切,用T4 DNA连接酶将XSYVrh片段连接到载体pART27上,成功构建了同时含4种病毒CP基因片段的植物表达载体pART27XSYVrh。采用直接转化法将植物表达载体导入根癌农杆菌LBA4404中,并利用农杆菌介导法对烟草品种T12试管苗进行遗传转化,转化后的烟草植株经PCR检测,有40株转化植株可扩增出目的条带,表明XSYVrh融合基因已成功转入烟草基因组中。
关键词: 马铃薯病毒, 融合基因, 载体构建, 遗传转化, 转基因烟草
中图分类号: S532
文献标识码: A
文章编号: 10003142(2017)01008709
Abstract: In order to simultaneously foster antifourvirus potato varieties(PVX, PVS, PVY and PLRV), four different viral coat protein (CP) gene PVXCP (670 bp), PVSCP(800 bp), PVYCP(700 bp) and PLRVCP(600 bp) were obtained via RTPCR and sequenced to confirm respectively. And the comparison of the sequences that we obtained and the already reported sequences from NCBI database showed that all four viral CP genessequences were more than 90% homologous; then around 300 bp size conservative gene fragments PVXrh, PVSrh, PVYrh, PLRVrh were selected from their respective viral CP genesand four specific bands which were consistent with the fragment size were obtained via PCR amplification. The fusion sequence XSYVrh which is around 1 200 bp long was created with PVXrh, PVSrh, PVYrh and PLRVrh gene fragments via OverlapPCR technique. With the help of DNA recombination technique, we integrated XSYVrh sequence into pGMT vector and created cloning vector pGMTXSYVrh. The cloning vector pGMTXSYVrh and the plant expression vector pART27 were treated with incision enzyme Spe Ⅰ and Sac Ⅰ; then under the effect of T4 DNA ligase, XSYVrh sequence was integrated with pART27 expression vector; at last pART27XSYVrh plant expression vector was successfully constructed. The pART27XSYVrh plant expression vector was introduced into Agrobacterium tumefaciens LBA4404, and subsequently introduced into tobacco (T12) assisted by the agrobacteriummediated transformation. PCR results showed that there were 40 transgenic plants with targeted gene integrated into their genomes.
Key words: potato virus, fusion gene, vector construction, genetic transformation, transgenic tobacco
馬铃薯(Solanum tuberosum)为茄科(Solanceae)茄属(Solanum)一年生草本块茎植物,起源于秘鲁、哥伦比亚及玻利维亚安第斯山区,在哥伦布发现新大陆后从原产地迅速向世界各地传播种植,目前马铃薯种植已遍布全球(李婷婷,2014)。马铃薯作为仅次于小麦、水稻和玉米的第四大粮食作物,在农业生产中有着其他作物不可替代的作用(张丽等, 2015)。近年来,随着马铃薯产业迅速发展,对其品质和产量等要求也不断提高,但马铃薯病毒病也日趋严重,且已成为马铃薯退化和减产的重要原因(朴福万,2010;吴兴泉等,2011)。马铃薯病毒病分布于世界各马铃薯种植区,目前已报道侵染马铃薯的病毒有40余种(Grammatikaki et al,2007),其中危害较重的主要有马铃薯卷叶病毒(Potato leaf roll virus,PLRV)、马铃薯Y病毒(Potato virus Y,PVY)、马铃薯X病毒(Potato virus X,PVX)、马铃薯S病毒(Potato virus S,PVS)、马铃薯M病毒(Potato virus M,PVM)、马铃薯A病毒(Potato virus A,PVA)和马铃薯纺锤块茎类病毒(Potato spindle tuber viroid,PSTV)等(马雪青等,2010)。单独一种马铃薯病毒一般可导致马铃薯减产10%~30%,严重者在80%以上(Salazar et al, 1978)。如PLRV在我国北方地区造成的马铃薯产量的损失为30%~40%,严重时候为80%~90%(霍晓辉等,2013);PVY严重时减产在80%以上(Glais et al,2002;Nolte et al,2004;Whitworth et al,2006;常飞等,2015);PVS可减产10%~20%,该病毒不易觉察,主要靠接触传毒,通过热处理及茎尖脱毒技术都较难脱除干净,分布于世界各马铃薯种植区(吴兴泉等,2015);PVX单一侵染症状轻微或潜隐,一般减产10%左右,有时可达50%(姚东校等,2013);马铃薯感染PVA后可造成40%的减产(张维,2013)。而2种甚至几种病毒混合侵染带来的损失远大于各病毒单独侵染(崔晓江等,1994),如PVY和PVX或PVY和PLRV混合侵染带来的的损失远远大于各病毒单独侵染(崔晓江等,1994)。因此,培育抗病毒马铃薯品种是防治病毒病的有效方法。
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