Department of Agronomy and Interdepartmental Genetics Graduate Major Program, Iowa State University, Ames, IA 50011-1010, USA.
Mol Plant Microbe Interact. 2012 Jun;25(6):817-24. doi: 10.1094/MPMI-12-11-0317.
Plants do not produce antibodies. However, plants can correctly assemble functional antibody molecules encoded by mammalian antibody genes. Many plant diseases are caused by pathogen toxins. One such disease is the soybean sudden death syndrome (SDS). SDS is a serious disease caused by the fungal pathogen Fusarium virguliforme. The pathogen, however, has never been isolated from diseased foliar tissues. Thus, one or more toxins produced by the pathogen have been considered to cause foliar SDS. One of these possible toxins, FvTox1, was recently identified. We investigated whether expression of anti-FvTox1 single-chain variable-fragment (scFv) antibody in transgenic soybean can confer resistance to foliar SDS. We have created two scFv antibody genes, Anti-FvTox1-1 and Anti-FvTox1-2, encoding anti-FvTox1 scFv antibodies from RNAs of a hybridoma cell line that expresses mouse monoclonal anti-FvTox1 7E8 antibody. Both anti-FvTox1 scFv antibodies interacted with an antigenic site of FvTox1 that binds to mouse monoclonal anti-FvTox1 7E8 antibody. Binding of FvTox1 by the anti-FvTox1 scFv antibodies, expressed in either Escherichia coli or transgenic soybean roots, was initially verified on nitrocellulose membranes. Expression of anti-FvTox1-1 in stable transgenic soybean plants resulted in enhanced foliar SDS resistance compared with that in nontransgenic control plants. Our results suggest that i) FvTox1 is an important pathogenicity factor for foliar SDS development and ii) expression of scFv antibodies against pathogen toxins could be a suitable biotechnology approach for protecting crop plants from toxin-induced diseases.
植物不产生抗体。然而，植物可以正确组装编码哺乳动物抗体基因的功能性抗体分子。许多植物疾病是由病原体毒素引起的。一种这样的疾病是大豆猝死综合征（SDS）。SDS 是由真菌病原体尖孢镰刀菌引起的严重疾病。然而，病原体从未从患病的叶片组织中分离出来。因此，病原体产生的一种或多种毒素被认为会导致叶片 SDS。其中一种可能的毒素 FvTox1 最近被鉴定出来。我们研究了在转基因大豆中表达抗 FvTox1 单链可变片段（scFv）抗体是否可以赋予对叶片 SDS 的抗性。我们已经创建了两个 scFv 抗体基因，Anti-FvTox1-1 和 Anti-FvTox1-2，它们分别编码来自表达抗 FvTox1 7E8 单克隆抗体的杂交瘤细胞系的 RNA 的抗 FvTox1 scFv 抗体。两种抗 FvTox1 scFv 抗体都与 FvTox1 的一个抗原结合位点相互作用，该位点结合抗 FvTox1 7E8 单克隆抗体。在硝酸纤维素膜上最初验证了在大肠杆菌或转基因大豆根中表达的抗 FvTox1 scFv 抗体与 FvTox1 的结合。与非转基因对照植物相比，稳定转化的大豆植物中抗 FvTox1-1 的表达导致叶片 SDS 抗性增强。我们的结果表明：i）FvTox1 是叶片 SDS 发展的重要致病性因素；ii）表达针对病原体毒素的 scFv 抗体可能是保护作物植物免受毒素诱导疾病的一种合适的生物技术方法。
