Epiphytic ecology and nutrition for control of a wheat pathogen

控制小麦病原体的附生生态学和营养

• 批准号: MR/Y020103/1
• 负责人: Helen Eyles
• 金额: $ 75.68万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FY020103%2F1
• 关键词: Epiphytic; ecology; nutrition; control; wheat

My research concerns a fungus, Zymoseptoria tritici (Zt), which attacks wheat plants, causing a disease known as Septoria tritici blotch (STB). STB costs the UK around £300 Million per year in lost wheat yields and in the cost of the fungicide used on the crops. Worse, the fungus is developing resistance to the fungicides available to treat it. This means that we need new methods to control the infection. To develop new ways to control Zt, it is necessary to gain a full understanding of the ways in which the fungus interacts with the wheat plant, and how that interaction can be affected by environmental conditions. In previous work, I showed that some isolates of Zt can grow on the leaf surface for around ten days before invading. The amount and duration of leaf surface growth varies between fungal isolates, and also when the same isolate infects different wheat varieties. Most plant pathogenic fungi, by contrast, can't obtain enough nutrients on the leaf surface to survive for more than 24 h. My FLF research programme aimed to determine the importance of this leaf surface growth phase for Zt, whether it is related to disease severity, and how inter-isolate differences in epiphytic growth are encoded in the genome. To understand fungal survival on the leaf surface, my project also aimed to determine what nutrients the fungus is using during this period, and how it interacts with other leaf surface microbes. My team and I are currently describing the epiphytic phenotypes of over 60 GFP-tagged isolates across a panel of wheat cultivars with varying degrees of resistance. We are linking these data to the genotypes and metabolite uptake profiles of the isolates to build a complete picture of the mechanisms underpinning surface survival. We have identified previously undescribed behaviours in Zt, including the ability to form biofilms. We have also carried out extensive field sampling, and are studying the interactions between Zt and other leaf surface microbes. During the next phase of the project, I will focus on three objectives: First, I will create reporter strains to visualise differences in nutrient uptake between isolates with different epiphytic phenotypes. The genes used to create these reporter strains will be based on the information gathered in the project so far, concerning the genetic and metabolic differences underlying epiphytic phenotypes. The reporters will allow us to visualise, in real time, how different isolates respond to changes in leaf surface nutrient availability due to, for e.g., fertilisation or pollen deposition. I will use this information to propose changes in fungicide/fertiliser application regimes that will optimise disease control. Secondly, I have shown that Zt can form biofilms, which have greater resistance to stresses such as drying, high temperature, and fungicides than do non-biofilm cells. I will determine whether and when biofilm formation occurs under field conditions and whether biofilms alter the outcome of fungicide treatment or survival of the pathogen during, for example, a heatwave. This work will help to develop weather-sensitive fungicide regimes and maximise fungicide efficacy, thus minimising the risk of further fungicide resistance emerging. Thirdly, I will explore options arising from our work to develop biocontrol of Zt. I will search our field-collected epiphyte library for organisms linked to increased/decreased disease in our related field data. I will then conduct experiments to see whether those linked to low disease are viable as biocontrol agents or, conversely, whether those linked to increased disease can be controlled, for example by working with Exeter's Citizen Phage Library to find phages that infect them. These three objectives will provide significant increases in our understanding of Zt infection biology and ecology alongside novel disease control mechanisms, which can then be tested in collaboration with our agricultural partners.

我的研究涉及一种真菌，Zymoseptoria tritici（ZT），该真菌攻击小麦植物，导致一种称为Septoria tritici斑点（STB）的疾病。 STB每年的小麦产量损失约为3亿英镑，以及农作物中使用的杀菌剂的成本。更糟糕的是，真菌正在发展对可用于治疗的真菌的抗性。这意味着我们需要新的方法来控制感染。为了开发控制ZT的新方法，有必要充分了解真菌与小麦植物相互作用的方式，以及该相互作用如何受到环境条件的影响。在以前的工作中，我表明一些ZT的分离株可以在叶片表面生长大约十天，然后入侵。叶表面生长的量和持续时间在真菌分离株之间以及相同分离株感染时的小麦变化不同。相比之下，大多数植物致病真菌无法在叶片表面获得足够的营养，无法生存超过24小时。我的FLF研究计划旨在确定该叶片表面生长阶段对ZT的重要性，是否与疾病的严重程度有关，以及在基因组中如何编码附生增长的隔离间差异。为了了解叶片表面上的真菌存活，我的项目还旨在确定真菌使用的营养成分，以及它如何与其他叶子表面微生物相互作用。我和我的团队目前正在描述一群具有不同耐药性的小麦品种中60多个GFP标记的分离株的附生表型。我们将这些数据与分离株的基因型和代谢产物摄取谱相关联，以构建表面存活下的机制的完整图片。我们已经确定了ZT中先前未描述的行为，包括形成生物膜的能力。我们还进行了广泛的现场采样，并正在研究ZT和其他叶子表面微生物之间的相互作用。在项目的下一个阶段，我将重点关注三个目标：首先，我将创建报告基因菌株，以可视化不同附生表型的分离株之间营养摄取的差异。用于创建这些报告基因菌株的基因将基于迄今为止项目中收集的信息，涉及附生表型的遗传和代谢差异。记者将使我们能够实时可视化不同的隔离物如何应对叶片表面养分可利用性的变化，例如受精或花粉沉积。我将使用此信息提出将更改杀菌剂/肥料应用程序，以优化疾病控制。其次，我已经证明ZT可以形成生物膜，这些生物膜对干燥，高温和杀菌剂等应力具有更大的耐药性。我将确定在田间条件下是否以及何时发生生物膜形成，以及生物膜是否改变了杀真菌剂治疗的结果或病原体的存活率，例如热浪。这项工作将有助于开发对天气敏感的杀菌剂制度并最大化杀菌剂效率，从而最大程度地减少出现进一步杀菌剂耐药性的风险。第三，我将探讨我们的工作为开发ZT生物防治而产生的选择。我将搜索我们的现场收集的附生植物图书馆，以与我们相关的现场数据中疾病增加/减少有关的生物。然后，我将进行实验，以查看与低疾病相关的人是否可以作为生物防治药物可行，还是相反，是否可以控制与疾病增加的疾病相关的人，例如，与埃克塞特的公民噬菌体图书馆一起寻找感染了它们的噬菌体。这三个目标将使我们对ZT感染生物学和生态学以及新型疾病控制机制的理解可显着提高，然后可以与我们的农业伴侣合作进行测试。