Chemical signaling and nutrient exchange between plants and beneficial rhizobacteria

Supervised by Dr Jake Bundy, Dr Patrik Jones and Dr Jörg Schumacher
Plant growth promoting (PGP) diazotrophs (biological nitrogen fixation) have great potential for reducing our dependency on applying chemical fertilisers in agriculture, which comes at tremendous economic and ecological costs. This project is embedded in a large initiative between Imperial, Oxford and the John Innes centre (BBSRC, BB_N003608/1) to better understand and potentially exploit the molecular communication between plants and plant associative diazotrophs and the nutrient trade-offs between them. The project has two interlinked but independent parts to mitigate risk:

1. We will investigate the molecular signaling and nutrient exchange between plant associative diazotrophs (including Klebsiella oxytoca, a rice associative diazotroph) and plant roots (including A. thaliana), where the former provide fixed nitrogen to the plant in return for fixed sugars. Using our established PGP setup and advanced metabolomics tools we will identify secondary metabolites and nutrients that diffuse between the diazotroph and the plant, revealing the chemical communication (including chemotaxis) and nutrient trade-offs (including carbon and nitrogen exchanges) between them. We will trace nutrient fluxes and build metabolic models and also investigate potential co-evolution between bacterial carbon source utilization and root exudates.

2. Our goal is to rebalance carbon-nitrogen trade-offs in favour of nitrogen delivery to plants. To do so, we will rebalance the bacteria’s nitrogen consumption (nitrogen assimilation) and nitrogen fixation (nitrogen production) – both processes depend on the alternative sigma54-RNA polymerase – using available and functional synthetic transcription activators that we have engineered in E.coli. These will be suitably adapted, tested and tuned in diazotrophs to achieve optimal trade-offs for crop growth.
Funding and Eligibility:
Applicants are expected to hold, or to be awarded a first class or a good upper second class BSc Degree, or an equivalent qualification, by October 2017.

The studentships are offered on a 1+3 basis (1 Year of Masters study followed by 3 years of PhD Research). In every case, the Masters Course will commence in October 2017 followed by the commencement of the PhD in October 2018. Only UK and EU students who meet the UK residency requirements are eligible to apply (minimum of three years of continuous residency in the UK immediately prior to the start of the PhD). Non-EU nationals are not eligible.

The studentships cover: (i) an annual tax-free stipend at the standard Research Council rate, (ii) contribution towards research costs, and (iii) tuition fees at the UK/EU rate.
How to apply:
Initial applications should include a full CV, names, addresses and contact details of two academic referees, a personal statement (500 words max) and a covering letter.

Completed applications should be submitted to the DTP Team via email ([Email Address Removed]) by 5pm on the 10th February 2017.

Please note only shortlisted applicants will be contacted by the project supervisors and we anticipate interviews will be taking place until the end of February.

Informal enquiries are welcomed and should be sent to Dr Jake Bundy [Email Address Removed] and/or Dr Jörg Schumacher [Email Address Removed]