DMSP cycling in unexpected places

科学背景：二甲基磺丙酸酯（DMSP）是一种由海洋藻类和细菌合成的海洋抗应激化合物。它在全球营养和硫循环、信号和微生物DMSP分解代谢中发挥关键作用，释放气候活性气体（CAG），特别是二甲基硫化物（DMS）。然而，许多陆生植物也会产生DMSP，包括全球种植面积为150 × 108公顷的小麦，并且在小麦根际样品中发现了相当高的DMSP水平。对于陆生植物环境中微生物DMSP的分解代谢知之甚少，关键问题仍未得到解答，例如，哪些微生物会降解植物产生的DMSP，它们使用哪些途径，它们对CAG的产生有什么影响？方法：这个多学科博士将解决这些未知的工作，在东英吉利亚小麦种植。该个人将对小麦种植园的DMSP生产和循环进行季节性实地研究。DMSP的产生、积累、微生物分解代谢和CAG通量将在植物组织和土壤中的过程（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/酶的测定）水平上进行研究，以探索其环境意义。为了补充这一过程主导的工作，博士将进行培养依赖（微生物富集，分离和模式生物的特征）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小麦样品中的DMSP作为营养物质，它们的生物多样性，使用的途径，释放的CAG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的DMSP循环基因对植物生长的促进作用。培训：学生将在东英吉利大学和PML接受跨学科的培训，包括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讲。

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.