Target-specific RNA-based bioprotectants for sustainable crop production in a changing climate

对农药对环境和人类健康的负面影响的担忧导致对环境可持续生产系统和“清洁食品”的需求日益增加。因此，欧洲议会通过了旨在减少化学植物保护产品使用的立法（第2009/128/EC号指令），并呼吁在整个欧洲深入重新考虑作物保护解决方案。BioProtect项目通过进一步开发细菌dsRNA生产平台，提供稳定有效的dsRNA制剂，以实现具有成本效益的作物保护，从而减少化学农药的使用。这项技术将通过生产在不同温度下稳定有效的dsRNA试剂，从而在全球变暖条件下为应对气候变化做好准备。dsRNA是一种天然来源的环境安全分子，存在于所有生物体中，并在土壤中迅速降解。它的应用触发RNA沉默，也称为RNA干扰（RNAi），这是一种正常的细胞机制，在植物，真菌，动物和人类的生长，发育，基因组稳定和防御病毒中起着至关重要的作用。此外，dsRNA具有触发模式触发免疫（Pattern-triggered immunity，PTI）的潜力，从而通过第二宿主防御途径加强作物保护。因此，当dsRNA被用作作物保护剂时，它作为一种强防御激活剂，增强植物利用自身细胞机制进行自我防御的能力。细菌dsRNA生产平台可以在发酵罐中生长，并使用dsRNA复制系统以大量生产高质量（hq）、>2500 bp长的“hq-dsRNA”。由该系统产生的hq-dsRNA在保护植物免受模型病毒感染方面是有效的。在BioProtect项目中，该技术将进一步发展为一种多功能系统，用于生产针对不同病毒和真菌病原体以及昆虫害虫的hq-dsRNA试剂和不同的hq-dsRNA制剂。将开发hq-dsRNA制剂以用于其作为天然来源的生物保护剂在温室和田间试验条件下保护蔬菜和谷类作物的适用性。将特别强调在储存和施用期间提供增加的hq-dsRNA稳定性、在目标作物喷洒时的有效吸收和活性的制剂，以及鉴定扩大规模和降低生产成本的决定因素。该项目将包括监测PTI与RNAi的激活，这可能影响靶特异性。鉴于气候变化，主要焦点将是确定hq-dsRNA制剂在不同干燥/湿度和环境温度条件下的效率，以鉴定在全球变暖条件下也具有活性的hq-dsRNA制剂。

Concerns over negative effects of pesticides on the environment and on human health cause an increasing demand for environmentally sustainable production systems and „clean food”. Accordingly, the European Parliament has adopted legislation (Directive 2009/128/EC) aiming at reducing the use of chemical plant protection products and calling for an in-depth reconsideration of crop protection solutions throughout Europe. The BioProtect project contributes to reducing the application of chemical pesticides through further development of a bacterial dsRNA production platform for the delivery of stable and efficient dsRNA formulations for cost-effective crop protection. This technology will be prepared for readiness to climate change by producing dsRNA agents that are stable and effective at different temperatures, thus under global warming conditions. dsRNA is a nature-derived and environmentally safe molecule that occurs in all organisms and is rapidly degraded in soils. Its application triggers RNA silencing, also known as RNA interference (RNAi), which is a normal cellular mechanism playing a crucial role in growth, development, genome stabilization, and defense against viruses in plants, fungi, animals, and humans. In addition, dsRNA has the potential to trigger pattern-triggered immunity (PTI) and, thus, to reinforce crop protection through a second host defense pathway. Thus, when dsRNA is applied as a crop protection agent, it acts as a strong defense activator that enhances the ability of plants to defend themselves using their own cellular mechanisms. The bacterial dsRNA-production platform can be grown in fermenters and uses a dsRNA replicating system to produce high-quality (hq), >2500 bp long “hq-dsRNAs” in high amounts. hq-dsRNAs produced by this system are effective in protecting plants against infection by a model virus. Within the BioProtect project this technology will be further developed as a versatile system to produce hq-dsRNA agents and different hq-dsRNA formulations targeted against different viral and fungal pathogens as well as insect pests. The hq-dsRNAs formulations will be developed for their applicability as nature-derived bio-protectants for protection of vegetable and cereal crops under greenhouse and field test conditions. Particular emphasis will be given to formulations that provide increased hq-dsRNA stability during storage and application, efficient uptake and activity upon target crop spraying, and to the identification of determinants for upscaling and low production costs. The project will include the monitoring of activation of PTI versus RNAi, which may influence target specificity. In the light of climate change, a major focus will be on determining the efficiency of hq-dsRNA formulations at different dryness/wetness and environmental temperature conditions in order to identify hq-dsRNA formulations that will be active also under conditions of global warming.