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

目前的世界农业严重依赖化学投入来提供生长所需的养分以及植物健康所需的杀虫剂和杀菌剂。为了确保未来农业的可持续性，必须找到其他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，由于欧盟杀虫剂和杀菌剂条例的变化，可用于防治虫害和病原体攻击的产品范围已大大减少。此外，消费者对食品供应商和超市都施加了越来越大的压力，要求他们提供不含农药的产品。这些驱动因素现在开始影响植物基础研究，这些研究旨在更好地了解植物对生物(和非生物)胁迫的反应，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，从而允许采取更有针对性的方法进行化学和其他干预。植物产生多种挥发性有机化学品(VOCs)。特定植物物种的VOC谱是独一无二的；然而，当植物受到生物或非生物胁迫时，这种谱可能会改变。这些化合物在植物中具有多种功能，既可以作为信号剂，也可以作为生物胁迫(食草动物、病原体)的直接和间接保护剂，以及非生物胁迫(高温、氧化剂)的保护剂。该项目的目的是确定是否有可能在选定的植物物种中检测、诊断和区分生物和非生物胁迫。我们已经在使用番茄的初步工作中证明了这在叶水平上是可能的(Laothawornkitkul等人，环境)。SCI。Technol，22,8433-8438,2008)，但不是整个工厂、玻璃屋或田野规模。我们将使用小麦和油菜作为田间种植作物的例子，以及草莓，通常在田间种植，但在英国越来越多地作为受保护的作物种植。将以蚜虫为模式害虫，以灰霉病菌为坏死性病原菌，以白粉病为生态型。为了促进这项工作，我们将在必要时使用最先进的质子转移反应质谱仪(PTR-MS)和质子转移反应飞行时间质谱仪(PTR-ToF-MS)和气相色谱-质谱仪(GC-MS)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，这名学生将在奥地利的Ionicon工作12个月，使用他们最新的PTR-ToF-MS仪器，以产生更详细的质量比数据。学生在Ionicon就学期间，将寻求机会与因斯布鲁克大学涡旋协方差通量测量方面的专家进行知识交流，以期可能将工作扩展到实地范围。在受控和田间条件下的剖面图的比较，将能够评估非生物参数的变化对健康的对照植物的挥发性剖面的影响，而不是那些受到生物因素挑战的植物。因此，在项目中，学生将调查和测量：健康植物的VOC谱；指定特定疾病或有害生物的标志性化学物质/谱；检测VOC谱变化所需的感染或感染程度；在存在或不存在虫害或病原体的情况下，水状况变化对VOC谱的影响；在非生物变化不受控制的“真实世界”情况下，如何修改此类谱。这将为学生提供一系列全厂和化学检测技术的培训。该项目和产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产出。

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.