Rao K V, Rathore K S, Hodges T K, Fu X, Stoger E, Sudhakar D, Williams S, Christou P, Bharathi M, Bown D P, Powell K S, Spence J, Gatehouse A M, Gatehouse J A
Department of Botany & Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.
Plant J. 1998 Aug;15(4):469-77. doi: 10.1046/j.1365-313x.1998.00226.x.
Snowdrop lectin (Galanthus nivalis agglutinin; GNA) has been shown previously to be toxic towards rice brown planthopper (Nilaparvata lugens; BPH) when administered in artificial diet. BPH feeds by phloem abstraction, and causes 'hopper burn', as well as being an important virus vector. To evaluate the potential of the gna gene to confer resistance towards BPH, transgenic rice (Oryza sativa L.) plants were produced, containing the gna gene in constructs where its expression was driven by a phloem-specific promoter (from the rice sucrose synthase RSs1 gene) and by a constitutive promoter (from the maize ubiquitin ubi1 gene). PCR and Southern analyses on DNA from these plants confirmed their transgenic status, and that the transgenes were transmitted to progeny after self-fertilization. Western blot analyses revealed expression of GNA at levels of up to 2.0% of total protein in some of the transgenic plants. GNA expression driven by the RSs1 promoter was tissue-specific, as shown by immunohistochemical localization of the protein in the non-lignified vascular tissue of transgenic plants. Insect bioassays and feeding studies showed that GNA expressed in the transgenic rice plants decreased survival and overall fecundity (production of offspring) of the insects, retarded insect development, and had a deterrent effect on BPH feeding. gna is the first transgene to exhibit insecticidal activity towards sap-sucking insects in an important cereal crop plant.
雪花莲凝集素（Galanthus nivalis agglutinin；GNA）先前已被证明，当添加到人工饲料中时，对稻褐飞虱（Nilaparvata lugens；BPH）具有毒性。稻褐飞虱通过吸食韧皮部取食，会导致“虱烧”，同时它也是一种重要的病毒传播媒介。为了评估gna基因赋予对稻褐飞虱抗性的潜力，培育了转基因水稻（Oryza sativa L.）植株，其构建体中含有gna基因，该基因的表达分别由韧皮部特异性启动子（来自水稻蔗糖合酶RSs1基因）和组成型启动子（来自玉米泛素ubi1基因）驱动。对这些植株的DNA进行PCR和Southern分析，证实了它们的转基因状态，并且转基因在自花授粉后传递给了后代。Western印迹分析显示，在一些转基因植株中，GNA的表达量高达总蛋白的2.0%。如通过对转基因植株非木质化维管组织中该蛋白进行免疫组织化学定位所示，由RSs1启动子驱动的GNA表达具有组织特异性。昆虫生物测定和取食研究表明，转基因水稻植株中表达的GNA降低了昆虫的存活率和总体繁殖力（后代产量），延缓了昆虫发育，并对稻褐飞虱的取食具有抑制作用。gna是第一个在重要谷类作物中对吸食性昆虫表现出杀虫活性的转基因。
