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。要实现未来的粮食安全，至少需要增加60%的粮食产量[1]。作物保护(CP)产品(除草剂、杀虫剂和杀菌剂)是为应对这一全球挑战而设计的，生产的植物需要更少的水，提供更高的产量，并防止昆虫、杂草和疾病。了解有效成分在目标叶片系统中的特性和分布，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，同时将对环境的影响降至最低，具有关键意义。该项目将探索现有的和新兴的质谱学成像(MSI)技术的新应用，以测量有效成分在叶片和植物中的吸收、分布和新陈代谢的改善[2]。与目前的方法相比，MSI提供的优势是研究可以在项目流水线的早期进行，在较短的时间尺度内产生关于活性成分(或其代谢物)和内源物种的更丰富的数据。MSI涵盖多种技术(MALDI、DESI、Nano/ToF-SIMS、LAESI等)，这些技术彼此高度互补，并与放射自显影或显微光谱技术相结合，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，不需要样品制备，提供50-100微米的空间分辨率，包括通常在干燥过程中损失的挥发性代谢物[4]。MALDI允许获得更大的质量范围，包括分辨率为10微米的生物聚合物。SIMS提供0.1-1um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]。这个BBSRC-CASE博士项目是与作物保护领域的世界市场领先者先正达合作的。其目的是开发可移植的协议，利用多重质谱学和互补技术研究重要的叶系统。MSI技术将根据包括灵敏度、特异度等性能标准进行评估和基准。该项目将使用优化的方法，然后使用各种剂量/配方方案研究CP产品在不同植物/叶片物种中的分布。在所有阶段，学生都将受益于凯斯合作伙伴先正达在植物科学和成熟的生物成像方法以及曼彻斯特大学的质谱学成像方面的世界领先专业知识。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.