On-line detection and diagnosis of plant damage and stress by herbivores and pathogens

目前世界农业严重依赖化学投入来提供生长所需的营养以及植物健康所需的杀虫剂和杀真菌剂。为了确保未来农业的可持续性，必须找到替代方法来确保和提高作物产量，同时减少对化学资源的依赖，以提供健康和高产的作物。在欧洲，由于欧盟农药和杀真菌剂法规的变化，可用于防治害虫和病原体攻击的产品范围已经大大减少。此外，消费者对食品供应商和超市施加越来越大的压力，要求它们提供不含农药的产品。这些驱动因素现在开始影响基础植物研究，其目的是更好地了解植物如何应对生物（和非生物）胁迫，最终目的是确定检测，监测和诊断生物（和非生物）胁迫的新方法，从而允许更有针对性的化学和其他干预措施。植物产生各种挥发性有机化学品（VOCs）。特定植物物种的VOC概况是独特的;然而，当植物受到生物或非生物胁迫时，该概况可能会发生变化。这些化合物在植物中具有许多功能，作为信号传导剂，作为针对生物胁迫（食草动物、病原体）的直接和间接保护剂，以及作为针对非生物胁迫（高温、氧化剂）的保护剂。该项目的目的是确定是否有可能检测、诊断和区分某些植物物种的生物和非生物胁迫。我们已经在使用番茄的初步工作中表明这在叶水平上是可能的（Laothawornkitkul等人，Environ. Sci.技术人员：22，8433 - 8438，2008），但不是在整个工厂、玻璃房或田间规模。我们将使用小麦和油菜作为大田作物的例子，草莓通常在田间生长，但在英国越来越多地作为受保护作物种植。蚜虫将用作模式害虫，葡萄孢属作为坏死营养型病原体，白粉病作为活体营养型。为了促进这项工作，我们将在必要时使用质子转移反应质谱（PTR-MS）和质子转移反应-飞行时间-质谱（PTR-ToF-MS）以及气相色谱-质谱（GC-MS）的最新技术进行化合物验证。最初的实验将在兰开斯特大学使用PTR-MS和GC-MS进行，然后学生将在奥地利的Ionicon工作12个月，使用他们最新的PTR-ToF-MS仪器，以生成更详细的质量特定数据。当学生在Ionicon实习时，将寻求机会让他/她与因斯布鲁克大学的涡动协方差通量测量专家进行知识交流，以期将工作扩展到现场规模。在控制和现场条件下的配置文件的比较，将能够评估如何改变非生物参数的健康，控制植物的挥发性配置文件的影响相比，那些挑战的生物因素。因此，在该项目中，学生将调查和测量：健康植物的VOC概况;指定特定疾病或害虫的签名化学品/概况;为了检测VOC概况的变化所需的侵扰或感染水平;在存在或不存在害虫或病原体的情况下，改变水状态对VOC概况的影响;在非生物变化不受控制的“现实世界”情况下，这些概况是如何修改的。这将使学生在一系列的整个工厂和化学检测技术的培训。该项目和工业合作不仅旨在提供一流的研究培训，而且还旨在产生适合博士论文的一流科学成果。

Current world agriculture is heavily dependent on chemical inputs to deliver both nutrients for growth and pesticides and fungicides for plant health. To ensure sustainability of agriculture in the future, alternative ways have to be found to secure and increase crop yields whilst reducing the reliance on chemical resources to deliver healthy and productive crops. In Europe the range of products available to combat pest and pathogen attack has already been significantly reduced as a result of changes to EU pesticide and fungicide regulations. In addition there is increasing pressure by consumers on food suppliers and supermarkets alike, to deliver products that are pesticide-free. These drivers are now beginning to influence fundamental plant research which aims to better understand how plants respond to biotic (and abiotic) stresses, with the ultimate aim of identifying novel methods for detecting, monitoring and diagnosing biotic (and abiotic) stresses, and hence allowing more targeted approaches to chemical and other interventions. Plants produce a wide range of volatile organic chemicals (VOCs). The VOC profile for a particular plant species is unique; however that profile can change when a plant is subjected to biotic or abiotic stress. These compounds have a number of functions in plants, as signalling agents, as direct and indirect protectants against biotic stress (herbivores, pathogens) and as protectants against abiotic stresses (high temperature, oxidants). The aim of this project is to determine if it is possible to detect, diagnose and differentiate biotic and abiotic stresses in selected plant species. We have already shown this is possible at the leaf-level in preliminary work using tomato (Laothawornkitkul et al, Environ. Sci. Technol., 22, 8433 - 8438, 2008) but not at the whole plant, glass house or field scales. We will use wheat and oilseed rape as examples of field grown crops, and strawberry, often grown in the field but increasingly grown as a protected crop in the UK. Aphids will be used as the model pest, together with Botrytis as a necrotrophic pathogen and powdery mildew as a biotroph. To facilitate this work we will use the state of the art technologies of proton transfer reaction mass spectrometry (PTR-MS) and proton transfer reaction - time of flight - mass spectrometry (PTR-ToF-MS) with gas chromatography - mass spectrometry (GC-MS) for compound verification where necessary. Initially experiments will be conducted at Lancaster University using PTR-MS and GC-MS. The student will then work at Ionicon in Austria for 12 months, using their latest PTR-ToF-MS instrument, to generate more detailed mass-specific data. Whilst the student is on placement at Ionicon, opportunities will be sought for him/her to have knowledge exchange with experts in eddy covariance flux measurements at the University of Innsbruck, with a view to the possible extension of the work to the field scale. A comparison of profiles under controlled and field conditions will enable an assessment of how changing abiotic parameters impact upon the volatile profile of healthy, control plants compared to those challenged by biotic factors. In the project the student will therefore investigate and measure: the VOC profile of healthy plants; signature chemicals/profiles that designate a particular disease or pest; the level of infestation or infection required in order to detect a change in VOC profile; the impact of changing water status on VOC profiles in the presence or absence of pest or pathogens; how such profiles are modified in a 'real-world' situation where abiotic changes are uncontrolled. This will give the student training in a range of whole plant and chemical detection techniques. The project and industrial collaboration are designed not only to give first-class research training but also to produce first-class scientific output suitable for a PhD thesis.