Department of Plant Pathology, School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa,
Transgenic Res. 2014 Apr;23(2):377-88. doi: 10.1007/s11248-013-9759-7. Epub 2013 Oct 25.
Multiple infections of Sweet potato feathery mottle virus (SPFMV), Sweet potato chlorotic stunt virus (SPCSV), Sweet potato virus G (SPVG) and Sweet potato mild mottle virus (SPMMV) cause a devastating synergistic disease complex of sweet potato (Ipomoea batatas Lam.) in KwaZulu-Natal, South Africa. In order to address the problem of multiple virus infections and synergism, this study aimed to develop transgenic sweet potato (cv. Blesbok) plants with broad virus resistance. Coat protein gene segments of SPFMV, SPCSV, SPVG and SPMMV were used to induce gene silencing in transgenic sweet potato. Transformation of apical tips of sweet potato cv. Blesbok was achieved by using Agrobacterium tumefaciens strain LBA4404 harboring the expression cassette. Polymerase chain reaction and Southern blot analyses showed integration of the transgenes occurred in six of the 24 putative transgenic plants and that all plants seemed to correspond to the same transformation event. The six transgenic plants were challenged by graft inoculation with SPFMV, SPCSV, SPVG and SPMMV-infected Ipomoea setosa Ker. Although virus presence was detected using nitrocellulose enzyme-linked immunosorbent assay, all transgenic plants displayed delayed and milder symptoms of chlorosis and mottling of lower leaves when compared to the untransformed control plants. These results warrant further investigation on resistance to virus infection under field conditions.
多种甘薯羽状斑驳病毒（SPFMV）、甘薯黄脉病毒（SPCSV）、甘薯花叶病毒（SPVG）和甘薯轻斑驳病毒（SPMMV）的感染会导致南非夸祖鲁-纳塔尔省甘薯毁灭性的协同病害。为了解决多种病毒感染和协同作用的问题，本研究旨在培育具有广谱抗病毒能力的转基因甘薯（cv. Blesbok）植株。利用 SPFMV、SPCSV、SPVG 和 SPMMV 的外壳蛋白基因片段在转基因甘薯中诱导基因沉默。采用携带表达盒的根癌农杆菌菌株 LBA4404 对 Blesbok 甘薯的顶芽进行转化。聚合酶链反应和 Southern blot 分析表明，在 24 个假定的转基因植株中有 6 个整合了转基因，并且所有植株似乎都对应于相同的转化事件。用 SPFMV、SPCSV、SPVG 和 SPMMV 感染的Ipomoea setosa Ker 对 6 个转基因植株进行嫁接接种挑战。尽管使用硝酸纤维素酶联免疫吸附试验检测到了病毒的存在，但与未转化的对照植株相比，所有转基因植株的下部叶片出现了褪绿和斑驳症状，但症状出现延迟且症状较轻。这些结果表明在田间条件下对病毒感染具有进一步的抗性研究价值。
