Mass Spectrometry Imaging of xenobiotics in foliar systems

到2050年，预计将有40亿人生活在缺水国家，面临粮食短缺。至少需要增加60%的粮食产量才能实现未来的粮食安全[1]。作物保护（CP）产品（除草剂、杀虫剂和杀真菌剂）旨在应对这一全球性挑战，生产出需要更少水、产量更高、免受昆虫、杂草和疾病侵害的植物。了解目标叶面系统中活性成分的特性和分布对于评估CP项目化合物和帮助农民生产安全，营养和负担得起的食品，同时最大限度地减少环境影响至关重要。该项目将探索已建立和新兴的质谱成像（MSI）技术的新应用，以测量叶片和植物中活性成分的吸收，分布和代谢。MSI相对于当前方法的优势在于，研究可以在项目管道的早期进行，从而产生关于活性成分身份的更丰富的数据（或其代谢产物）和内源性物种在较短的时间尺度。MSI涵盖多种技术（MALDI、DESI、Nano/ToF-SIMS、LAESI等），它们彼此高度互补，并且与放射自显影或显微光谱技术高度互补，为空间代谢组学提供独特的分子数据[3]。DESI和LAESI在环境条件下分析样品，无需样品制备，空间分辨率为50-100 μ m，包括干燥过程中通常损失的挥发性代谢物[4]。MALDI允许访问扩展的质量范围，包括10 μ m分辨率的生物聚合物。西姆斯提供0.1-1 um分辨率的原子/小分子成像，用于在亚细胞尺度上追踪代谢物[5]。该BBSRC-CASE博士项目与作物保护领域的全球市场领导者先正达合作。其目的是开发可转让的协议，研究重要的叶系统使用多种质谱和互补技术。MSI技术将根据性能标准进行评估和基准测试，包括灵敏度，特异性等。使用优化的方法，该项目将使用各种剂量/配方方案研究CP产品在不同植物/叶物种中的分布。在所有阶段，学生将受益于CASE合作伙伴先正达在植物科学和既定生物成像方法以及曼彻斯特大学质谱成像方面的世界领先的专业知识。学生将获得每年2500英镑的助学金。

By 2050 it is expected that 4 billion of people will be living in countries with water scarcity, facing food shortages. At least 60% greater food production is needed to deliver future food security [1]. Crop Protection (CP) products (herbicides, insecticides and fungicides) are designed to meet this global challenge, producing plants that require less water, provide higher yield and are protected from insects, weeds and diseases. Understanding the identity and distribution of active ingredients in target foliar systems is of key importance for assessing CP project compounds and helping farmers produce safe, nutritious and affordable food while minimising environmental impact. This project will explore the novel application of established and emerging mass spectrometry imaging (MSI) technologies to measure improved uptake, distribution and metabolism of active ingredients in leaves and plants [2]. The advantages that MSI offer over current approaches are that the studies can be conducted earlier in the project pipeline, producing richer data regarding the identity of the active ingredient (or it's metabolite) and endogenous species in shorter timescales.MSI covers multiple techniques (MALDI, DESI, Nano/ToF-SIMS, LAESI etc) which are highly complementary to each other and to autoradiography or micro-spectroscopy techniques, providing unique molecular data for spatial metabolomics [3]. DESI and LAESI analyse samples under ambient conditions with no sample preparation providing spatial resolution on the 50-100 um scale including volatile metabolites normally lost during drying [4]. MALDI allows access to extended mass range including biopolymers at 10 um resolution. SIMS offers atomic/small molecular imaging at 0.1-1 um resolution for tracing metabolites at the sub-cellular scale [5]. This BBSRC-CASE PhD project is in collaboration with Syngenta, a world market leader in crop protection. The aim is to develop transferable protocols for studying important foliar systems using multiple mass spectrometry and complementary techniques. MSI technologies will be evaluated and benchmarked against performance criteria including sensitivity, specificity etc. Using optimised methodology, the project will then study CP product distribution in different plant/leaf species using various dosing/formulation protocols. At all stages, the student will benefit from world-leading expertise at CASE partner Syngenta in plant science and established bioimaging methods, and in mass spectrometry imaging at the University of Manchester. The student will receive a stipend enhancement of £2500 p.a.