Dimethylsulfoniopropionate (DMSP) is one of the Earth’s most abundant organosulfur compounds. It is an antistress compound with key roles in global nutrient and sulfur cycling, signalling and climate. Dinoflagellates produce the highest cellular concentrations of this influential compound of all organisms yet there is uncertainty about how these phytoplankton do so. Previously, we identified DMSP synthesis genes in algae and bacteria publishing our findings in Nature Microbiology in 2017, 18 and 19. This PhD aims to characterise the little-known dinoflagellate decarboxylase DMSP synthesis pathway, identify the key genes involved and determine how environmentally significant this pathway is.
The PhD project will use model dinoflagellates that produce high cellular levels of DMSP to investigate the process. The student will be taught how to grow and study the physiology of dinoflagellates at UEA and the University of Cambridge. Using analytical chemistry at UEA and the John Innes Centre (JIC), they will establish and characterise the dinoflagellate DMSP biosynthetic pathway/s. Molecular genetics and biochemistry will be used to identify and validate novel DMSP synthesis genes. The student will study whether environmental conditions affect DMSP production and the transcription of the DMSP synthesis genes to potentially determine the role/s of DMSP in our model dinoflagellates. Finally, using molecular ecology tools and bioinformatics, the diversity, abundance, activity and biogeography of DMSP-producing dinoflagellates and the synthesis genes will be assessed in natural marine environments. This PhD will strengthen our ability to assess the effects of e.g., climate change on DMSP cycling, and the significance of dinoflagellates in global organosulfur cycling.
Training will be provided in dinoflagellate physiology, molecular biology, biochemistry, molecular ecology, bioinformatics and metabolomics at UEA by Malin and Todd, at JIC by Truman and at the University of Cambridge by Waller.