RNA interference technologies to protect crop plants

昆虫通常被认为是我们在食物和纤维方面最严重的竞争对手，它们对植物造成损害，传播植物病原体，并导致储存的食物、纤维和木制品腐烂，从而降低作物产量。据估计，尽管我们努力控制最有害的害虫，但大多数国家的国民生产总值中仍有10%至20%被昆虫消耗或破坏。大多数防治措施依靠使用广谱合成农药来防治害虫。不幸的是，这些化学物质不仅会杀死害虫，还会杀死非目标的有益昆虫，并对其他无脊椎动物和脊椎动物产生不利影响。本研究的主要目的是评估用于农业的新的物种特异性农药，以减少对非目标物种的负面影响。将特别研究两种技术：RNA干扰（RNAi）和来自土壤细菌苏云金芽孢杆菌的杀虫蛋白（“Bt”蛋白）。RNAi是一项可以彻底改变害虫控制的新技术，因为它可以选择性地沉默害虫体内的特定基因，但不会影响其他不共享确切基因序列的物种。由于每个物种都是由其遗传密码的独特性来定义的，因此该技术可以适用于控制不同种植系统中的许多不同害虫。几十年来，通过鉴定具有窄宿主特异性的细菌来源的天然杀虫蛋白（从苏云金芽孢杆菌中获得），Bt技术已经得到了有效和安全的应用。Bt产品最初用于叶面应用，但最近在过去的20年里，已经确定了一些蛋白质，并将其用于转基因作物中，以选择性地杀死主要害虫。这些技术提供的植物虫害保护预计将提高作物产量，减少储存期间的损失，从而增加加拿大农民和农业工业的盈利能力。开发对环境更安全的方法来控制农业害虫也将使加拿大成为农业生物技术部门的领导者之一。

Insects are often considered our most serious competitors for food and fiber, reducing crop yields by inflicting damage to plants, propagating plant pathogens, and causing decay in stored food, fiber, and wood products. It has been estimated that insects consume or damage between 10 and 20% of the gross national products of most nations, despite our efforts to control the most noxious pests. Most control measures rely upon the use of broad-spectrum synthetic pesticides to control the pests. Unfortunately, these chemicals not only kill pests, but also kill non-target beneficial insects, and can adversely affect other invertebrate and vertebrate species. The primary objective of this research is to evaluate new species-specific pesticides for use in agriculture that may reduce negative impacts on non-target species. Two technologies in particular will be examined: RNA interference (RNAi) and insecticidal proteins derived from the soil bacterium Bacillus thuringiensis ("Bt" proteins). RNAi is a new technology that could revolutionize pest insect control, as it can selectively silence specific genes within the pests, but without affecting other species that do not share the exact gene sequences. As each species is defined by the uniqueness of its genetic code, this technology could be adapted to control many different pests in different cropping systems. Bt technology has been used effectively and safely for decades through the identification of bacterially-derived, natural insecticidal proteins with narrow host-specificities (obtained from Bacillus thuringiensis). Bt products were first used as foliar applications, but more recently during the past 20 years, select proteins have been identified and used in transgenic crops to selectively kill key insect pests. Plant protection from insect pests afforded by these technologies is expected to increase crop yields and reduce losses during storage, and consequently, increase profitability for Canada farmers and the agricultural industry. The development of environmentally-safer methods to controlling agricultural pests would also place Canada among the leaders in the agricultural biotechnology sector.