DMSP cycling in unexpected places

科学背景：二甲基磺基丙酸酯（DMSP）是一种由海洋藻类和细菌产生的抗应激化合物。它在全球养分和硫循环、信号和微生物DMSP催化剂释放气候活性气体（CAG），特别是二甲基硫（DMS）中发挥关键作用。然而，许多陆生植物也产生DMSP，包括全球种植面积超过2x 108公顷的小麦，在小麦根际样本中发现了可观的水平。关于陆生植物环境中微生物DMSP催化剂的知之甚少，关键问题仍然没有答案，例如什么微生物降解植物产生的DMSP，它们使用哪些途径以及它们对CAG生产的影响是什么？方法：这个多学科博士将通过在东安格利亚种植小麦来解决这些未知问题。个人将进行DMSP生产和小麦种植园循环的季节性实地研究。将在植物组织和土壤中/来自植物组织和土壤的过程（使用例如气相色谱、质谱和自主DMS传感器）和分子（使用例如RT-qPCR和关键基因/酶测定）水平上研究DMSP的产生、积累、微生物催化剂和CAG通量，以探索其环境意义。为了补充这一过程为主导的工作，博士将进行培养依赖（微生物富集，分离和模式生物的表征）和独立的微生物学（例如DNA稳定同位素探测和多组学分析），以确定微生物进口和分解代谢DMSP作为小麦样品中的营养素，其生物多样性，所使用的途径，CAG释放以及环境变化如何影响这些。最后，鼓励学生根据自己的兴趣发展项目，例如研究微生物分离物或新型DMSP循环基因的任何植物生长促进作用。培训内容：学生将在UEA和PML接受特殊的跨学科培训，涵盖DMSP生物学，分子生态学和微生物学，植物生理学，生物信息学，分析化学，实地考察以及科学写作和演示。

Scientific background: Dimethylsulfoniopropionate (DMSP) is known as a marine anti-stress compound made by marine algae and bacteria. It has key roles in global nutrient and sulfur cycling, signalling, and microbial DMSP catabolism releases climate-active gases (CAG), notably dimethylsulfide (DMS). However, DMSP is also produced by many terrestrial plants, including wheat that is farmed on >2x108 hectares globally, and is found at appreciable levels in wheat rhizosphere samples. Little is known about microbial DMSP catabolism in terrestrial plant settings and key questions remain unanswered, e.g. what microbes degrade plant-made DMSP, which pathways do they use and what is their impact on CAG production? Methodology: This multidisciplinary PhD will address these unknowns by working on wheat cropped in East Anglia. The individual will conduct a seasonal field-study of DMSP production and cycling on wheat plantations. DMSP production, accumulation, microbial catabolism and CAG flux will be investigated at the process (using e.g. gas chromatography, mass spectroscopy and autonomous DMS sensors) and molecular (using e.g. RT-qPCR and assays of key genes/enzymes) levels in/from plant tissue and soils - to explore their environmental significance. To complement this process-led work, the PhD will conduct culture-dependent (microbial enrichment, isolation and characterisation of model organisms) and -independent microbiology (e.g. DNA-stable isotope probing and multi-omics analysis) to identify microbes importing and catabolising DMSP as a nutrient in wheat samples, their biodiversity, the pathways used, the CAG liberated and how environmental changes impact these. Finally, the student will be encouraged to develop the project to their interests, e.g. to investigate any plant growth promoting effects of microbial isolates or novel DMSP cycling genes. Training: The student will receive exceptional interdisciplinary training at UEA and PML spanning DMSP biology, molecular ecology and microbiology, plant physiology, bioinformatics, analytical chemistry, fieldwork and in scientific writing and presentation.