The development of tools and resources for the identification of inhibitors of pigment biosynthetic pathways in the chloroplast.

背景。预计到2050年，全球人口将增长30%，达到92亿。为了养活这些人口，粮食产量需要增加70%。这种产量的增加必须以更少的土地、更少的水、更少的能源投入、化肥和化学品来实现。除草剂仍将是综合农药管理做法的重要组成部分；如果粮食生产要满足需求。30多年来，还没有一种具有新作用模式的新除草剂商业化，因此，抗性的威胁日益增加，需要在除草剂发现的早期阶段将重点放在作用模式（MOA）上。漂白除草剂被指定为导致绿色植物叶子白色漂白的化学物质。它们的有效性在于它们能够引起依赖光的单线态氧的产生，从而破坏脂质、叶绿素和蛋白质，导致植物死亡。漂白除草剂具有化学多样性，这反映了不同的叶绿体生物合成途径及其作用于这些途径中的单个成分。漂白除草剂之间的共同表型特征经常导致将moa分配给特定除草剂抑制剂的混淆。例如，去氟拉松是类胡萝卜素生物合成的抑制剂，特别是植物烯去饱和酶（PDS），[5]。抑制PDS导致前体植物烯积累。然而，植物烯也可以通过抑制质体醌/生育酚的生物合成而在营养组织中积累。这是因为质体醌作为一种辅助因子参与了植物烯的去饱和。科学原理和重要性。在这个培训方案中，将开发遗传资源、代谢物分析程序和体外测定，以便区分和验证不同的漂白除草剂。该方法将使用新技术和跨学科方法解决生物学问题，涉及化学，生物工程和高通量化合物筛选配方。这些有助于阐明除草剂MOA的方法对于新化学物质的快速评估和进展至关重要，可以在农业工业中应用时进行大规模筛选。

Background. The global population is projected to increase by 30% to 9.2 billion in 2050. In order to feed this population a 70% increase in food production is required [1]. This increased production must occur with less land availability, less water, less energy input, fertilizers and chemicals. Herbicides will remain an essential component of integrated pesticide management practices; if food production is to meet demand. No new herbicides have been commercialised with a novel mode of action for over 30 years [3], hence the increased threat from resistance, and the need to be able to focus efforts on Modes of action (MOA) at an earlier stage in herbicide discovery.Bleaching herbicides are designated as chemicals that cause white bleaching of green plant leaves. Their effectiveness resides in their ability to cause light-dependant generation of singlet oxygen which damages lipids, chlorophyll and proteins leading to plant death [4]. Bleaching herbicides are chemically diverse, which reflects the different chloroplastic biosynthetic pathways and the individual components within these pathways they effect. The common phenotypic traits between bleaching herbicides often causes confusion in assigning MOAs to specific herbicidal inhibitors. For example, Norflurazon, is an inhibitor of carotenoid biosynthesis, specifically the enzyme phytoene desaturase (PDS), [5]. Inhibition of PDS results in the precursor phytoene accumulating. However, phytoene can also accumulate in vegetative tissues from the inhibition of plastoquinone/tocopherol biosynthesis. This is because plastoquinone acts as a cofactor involved in phytoene desaturation.Scientific rationale and importance. In this training programme, genetic resources, metabolite profiling procedures and in vitro assays will be developed to enable the differentiation and validation of different bleaching herbicides. The approach will tackle the biological question using new technologies and an interdisciplinary approach, involving chemistry, bioengineering and formulations for high-throughput compound screening. These methodologies that facilitate the elucidation of herbicidal MOA are essential for the rapid assessment and progression of novel chemistries, allowing large-scale screening when applied in the agro-industry.