The Dixon group focuses on molecular understanding of biological nitrogen fixation in bacteria and its regulation in response to environmental cues.
Nitrogen-fixing bacteria are an essential component of the nitrogen cycle, a biological process that converts inert nitrogen into active molecules for use in plant and animal growth.
Ray studies how environmental signals, such as the presence of oxygen, fixed nitrogen and metal availability influence gene expression in nitrogen-fixing bacteria. These signalling mechanisms ensure efficient survival in nitrogen-depleted environments, but also can be potentially manipulated to increase fixed nitrogen supplied to crops.
While nitrogen fertilisers increase crop yields in overworked, nitrogen-depleted soils, they are also a major source of pollution and the greenhouse gas nitrous oxide. The engineering of new nitrogen-fixing bacteria could provide a biologically sustainable source of nitrogen to promote the growth of cereals.
Together with collaborators, Ray’s group also use synthetic biology approaches to define the minimal set of genetic determinants for nitrogen fixation that can be expressed in a eukaryotic host to produce active nitrogenase, with the long-term aim of directly engineering nitrogen fixation in plants.
Batista M. B., Chandra G., Monteiro R. A., de Souza E. M., Dixon R. (2018)Hierarchical interactions between Fnr orthologs allows fine-tuning of transcription in response to oxygen in Herbaspirillum seropedicaeNucleic Acids Research (46 (8))Publisher's version: 1362-4962
Yang J., Xie X., Xiang N., Tian Z. X., Dixon R., Wang Y. P. (2018)Polyprotein strategy for stoichiometric assembly of nitrogen fixation components for synthetic biology.Proceedings of the National Academy of Sciences of the United States of America (115)Publisher's version: 0027-8424
Batista M. B., Dixon R. (2019)Manipulating nitrogen regulation in diazotrophic bacteria for agronomic benefit.Biochemical Society Transactions (47(2))Publisher's version: 0300-5127