Engineering Nitrogen Fixation into Plants
Plant Biology PhD Projects
Project Summary
Nitrogen is an essential nutrient for plant growth, forming the backbone of macromolecules such as nucleic acids and proteins, and playing a central role in photosynthesis through its presence in pigments like chlorophyll.Although nitrogen gas (N2) makes up approximately 78% of the Earth’s atmosphere, plants are unable to use it directly. Instead, they rely on fixed forms of nitrogen, such as ammonia and nitrate, absorbed from the soil. In agricultural systems, lack of available forms of nitrogen can limit yield by up to 80%. While a number of plants, such as legumes, can obtain nitrogen via a symbiotic relationship with nitrogen-fixing bacteria (rhizobia) in their roots, the vast majority of crop species, including major cereals like wheat, rice and maize, lack this capability and rely heavily on exogenous nitrogen fertilizers to achieve optimal yields.
The production and use of exogenous fertilisers pose significant environmental and economic challenges. For example, synthetic fertiliser manufacturing consumes ~1% of global energy and contributes ~2% of global greenhouse gas emissions. Additionally, excessive use of fertiliser leads to environmental degradation through nitrate leaching and the eutrophication of water bodies. Thus, engineering nitrogen fixation directly into cereal crops has the potential to substantially improve yield in low input farming systems, to reduce the negative environmental impacts of high intensity farming systems, and thus provide a major leap towards more sustainable agriculture.
In this project, we aim to engineer the nitrogen fixation pathway from rhizobia into a major cereal crop. The PhD project can be tailored to the candidate’s interests, with opportunities to focus on one or more of the following key objectives:
- Discovering and developing new gene expression control mechanisms: Exploiting new synthetic biology approaches to achieve tuneable expression of genes required in the nitrogen-fixation pathway.
- Solving key bottlenecks and challenges via molecular engineering of pathway components: Using rapid plant cell-based assays to test concepts and pathways and develop new approaches to deployment in plants.
- Directed evolution: Use new synthetic biology and directed evolution approaches to solve critical bottlenecks and unlock new approaches for engineering nitrogen fixation into plants.
Potential Supervisors
Skills Recommended
- A strong interest and background in molecular biology, synthetic biology, plant biology, or a related discipline
- Experience with basic molecular biology techniques (e.g. cloning, PCR, transformation)
- Ability to work independently and as part of a collaborative research team
- Strong written and verbal communication skills.
Skills to be Developed (depends on research project)
- Synthetic biology
- High-throughput cell-based assays
- Directed evolution & protein design strategies
- Data analytics
- Cutting edge plant phenotyping
- Bioinformatic techniques for including transcriptomics analysis
- Written and oral scientific communication.
University DPhil Courses