SMART Bacteriophage Mixes: Sustainable Biocontrol for Onion Soft Rot

从全球来看，洋葱是第二大最受欢迎的蔬菜，年产量为9900万吨。在英国，蔬菜是消费量第四大的蔬菜，而且越来越受欢迎，最近的封锁增加了公众对吃蔬菜有益健康的认识，也增加了人们对家庭烹饪的热情。目前，国内洋葱产量仅满足英国约50%的需求（每年约80万吨），赤字由进口弥补，主要来自荷兰，但远至新西兰，与更大的环境影响和更高的总体价格相关，转嫁给客户。我们的愿景是让英国种植者能够全年种植、储存和供应洋葱到英国市场，增加经济价值并实施更可持续的生产方法。提高作物质量是提高生产力的关键，该项目将解决造成严重储藏腐烂的作物细菌感染问题，这些问题会导致作物没收、经济损失（每年850万英镑）和声誉受损。这些损失收紧了英国的供应，增加了对进口的依赖。迄今为止，由于缺乏对相关洋葱腐病病原体的详细了解，阻碍了有效控制腐病的发展，行业只能获得相对粗略的识别方法。该项目的创新重点在于使用新的病原体特征数据来确定控制措施，除了适用于328亿英镑的全球市场外，还为英国洋葱行业带来经济和环境附加值。关键目标是利用洋葱腐病病原体的新知识，开发一种基于噬菌体的可持续、低风险的生物防治方法；自然产生的，高度特异性的抗菌剂，杀死细菌，无非目标效应。牵头合作伙伴在开发植物保护技术方面取得了相当大的进展，但在相对小众的市场上，而且病原体特征往往有限，延长了开发时间。洋葱腐病病原体的生物学和遗传学以及来自更广泛的洋葱生长环境（微生物组）的病原体将被表征，有效地创建一个最普遍和最致命的洋葱腐病细菌的综合文库。这将成为噬菌体分离和更集中地匹配关键病原体的宝贵资源。目的是推导出一种中试噬菌体配方，并在实验室、温室和实地调查中研究控制腐烂方法的可行性。鉴于腐烂导致的损失对英国洋葱产业和更广泛的全球机会的影响，该项目解决了一个及时的机会。靶向病原体表征的新方法也将使领先的中小企业能够在快速增长的全球生物农药市场中最大化商业化机会。

Globally, onions are the second-most popular vegetable, with an annual production of 99 Million tonnes. In the UK, they are the fourth-most consumed vegetable and growing in popularity, with recent lockdowns increasing the publics' perceived health benefits of eating vegetables and enthusiasm for home cooking. Currently, home onion production fulfils only ˜50% of UK demand (˜800kt p.a.), with the deficit made up by imports, mainly from The Netherlands but as far away as New Zealand, associated with greater environmental impact and higher overall prices, passed onto the customer.**Our vision** is to allow UK growers to grow, store and supply onions to the UK market all-year-around, adding economic value and implementing more sustainable production methods. Improved-crop quality is key to increased productivity and this project will address bacterial-crop infections that produce significant in-store rots, resulting in crop right-offs, economic losses (£8.5M p.a.) and reputational damage. These losses tighten the UK supply, increasing the reliance on imports.To date, a lack of detailed knowledge of the relevant onion-rot pathogens has hampered the development of effective rot-disease control, with the industry having access to relatively cursory identification methods. This project's **innovation focus** lies in using new pathogen-characterisation data to target control measures, bringing both economic and environmental added value to the UK-onion sector, in addition to being applicable to the £32.8Bn global market.The **key objective** is to harness new knowledge of onion-rot pathogens to develop a sustainable, low-risk biological-control approach based on bacteriophage; naturally-occurring, highly-specific antimicrobial agents, which kill bacteria, with zero non-target effects. The lead partner has made considerable progress in developing the technology for plant protection but in relatively niche markets and with often limited pathogen characterisation extending development timelines. The biology and genetics of onion-rot pathogens and those from the wider-onion growing environment (microbiome) will be characterised, effectively creating a comprehensive library of the most prevalent and virulent onion-rot bacteria. This will act as a valuable resource for bacteriophage isolation and more focussed matching against key pathogens. The **aim** is to derive a pilot-bacteriophage formulation and investigate the feasibility of the rot-control approach, both in the laboratory, as well as in glasshouse and field investigations.The project addresses a timely opportunity given the impact of rot-induced losses on the UK onion industry and the wider global opportunity. New methods of targeted-pathogen characterisation will also enable the lead SME to maximise commercialisation opportunities, within a rapidly-growing global biopesticide market.