Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click on 'Find out more' to see our Cookie statement.

An interdisciplinary research collaboration between the Universities of Oxford and Cambridge has engineered a novel synthetic plant-microbe signalling pathway that could provide the foundation for transferring nitrogen fixation to cereals.

Published in Nature Communications today, the team of plant scientists, microbiologists and chemists used synthetic biology techniques to design and then engineer a molecular dialogue between plants and the bacteria surrounding their roots in a zone called the rhizosphere. This synthetic signalling system could be a vital step towards successfully engineering nitrogen-fixing symbiosis in non-legume crops like wheat and maize.

Enhancing the root microbiota has enormous potential for improving crop yields in nutrient-poor soils and reducing chemical fertiliser use.

Joint lead author, Dr Barney Geddes, from Oxford’s Department of Plant Sciences, said: ‘Plants influence the microbiota of their rhizosphere by sending out chemical signals that attract or suppress specific microbes. Engineering cereal plants to produce a signal to communicate with and control the bacteria on their roots could potentially enable them to take advantage of the growth-promoting services of those bacteria, including nitrogen fixation.

‘To do this we selected a group of compounds normally produced by bacteria in legume nodules, called rhizopines. First we had to discover the natural biosynthetic pathway for rhizopine production, and then design a synthetic pathway that was more readily transferred to plants. We were able to transfer the synthetic signalling pathway to a number of plants, including cereals, and engineer a response by rhizosphere bacteria to rhizopine.’

Joint lead author, Dr Amelie Joffrin, at Oxford developed a new stereoselective synthesis of key rhizopine. She said: ‘The synthetic chemistry was essential to provide compounds that enabled the investigation of rhizopine biosynthesis and its transfer from bacteria to plant. In particular, the rhizopines produced allowed us to confirm which was the naturally active enantiomer (“hand”) of a key bioactive compound.’

Dr Ponraj Paramasivan, joint lead author at Cambridge’s Sainsbury Laboratory, explained how the team transferred the rhizopine synthesis genes into barley to assess whether they could engineer rhizopine synthesis in cereals.

She said: ‘We confirmed the barley synthesised and then exuded rhizopine to its rhizosphere. We then measured the signalling between barley roots and rhizosphere bacteria and found a significant level of communication was occurring in most bacterial colonies. These results mean that we could potentially use this transkingdom signalling pathway to activate root microbiota to fix nitrogen, and a host of other plant growth-promoting services such as producing antibiotics or hormones or solubilising soil nutrients.

“A key advantage of this synthetic signalling pathway is that only the specific crop plant that is engineered to produce the signal will benefit. This means that weeds that currently benefit just as much as the target crop from the application of chemical fertilisers, will not benefit from these enhanced plant-microbe associations as they do not produce this novel signalling molecule to communicate with bacteria.”

Future work in the Poole, Oldroyd and Conway laboratories will focus on how plants can control key processes in root bacteria such as nitrogen fixation, phosphate solubilisation and plant growth promotion. This opens up the world of the bacterial microbiome and its diverse metabolism to control by plants and in particular the cereals. It is likely to be a key component in attempts to engineer nitrogen fixation into cereals.

Story courtesy of the University of Oxford News Office

Similar stories

‘Citizen scientists’ help researchers gather new insights into polar bear behaviour

Citizen science Research Zoology

Oxford University is working with Canadian researchers on a first-of-its-kind project that will engage citizen volunteers to help advance knowledge about polar bear behaviour in a changing environment by analysing a decade’s worth of images captured by trail cameras.

Winners announced for Oxford’s Beyond Boundaries art competition to encourage inclusion in STEM sciences

Equality and Diversity Materials science Plant sciences Statistics Zoology

Oxford University has today announced the winners of its science-inspired schools’ art competition Beyond Boundaries which was launched to encourage inclusion in science research

From The Conversation: Mars InSight: why we’ll be listening to the landing of the Perseverance rover

Earth sciences Physics Research The Conversation

Ben Fernando (Departments of Earth Sciences and Physics) writes about using the Insight mission to detect seismic signals during the landing of Perseverance - the first time that anyone has tried using a spacecraft on the surface of another planet to detect another spacecraft arriving.

New machine learning system developed to identify deteriorating patients in hospital

Biomedical engineering Medical science Research

Researchers in Oxford have developed a machine learning algorithm that could significantly improve clinicians’ ability to identify hospitalised patients whose condition is deteriorating to the extent that they need intensive care.

Science Blog: From rust to riches? Computing goes green...or is that brown?

Computer science Physics Research

Professor Paolo Radaelli from Oxford’s Department of Physics, working with Diamond Light Source, has been leading research into silicon alternatives and his group’s surprising findings are published in Nature on 4th February.

Getting the message right on nature-based solutions to climate change

Climate change Research Zoology

Nature‐based solutions can play a key role in helping to tackle the climate and nature crises, while delivering other benefits for people, according to a new paper today from the Nature-based Solutions Initiative (NbSI) at the University of Oxford - but it is vital to get the message right about how to deliver successful NbS and avoid potential pitfalls.

Similar stories

‘Citizen scientists’ help researchers gather new insights into polar bear behaviour

Citizen science Research Zoology

Oxford University is working with Canadian researchers on a first-of-its-kind project that will engage citizen volunteers to help advance knowledge about polar bear behaviour in a changing environment by analysing a decade’s worth of images captured by trail cameras.

Winners announced for Oxford’s Beyond Boundaries art competition to encourage inclusion in STEM sciences

Equality and Diversity Materials science Plant sciences Statistics Zoology

Oxford University has today announced the winners of its science-inspired schools’ art competition Beyond Boundaries which was launched to encourage inclusion in science research

From The Conversation: Mars InSight: why we’ll be listening to the landing of the Perseverance rover

Earth sciences Physics Research The Conversation

Ben Fernando (Departments of Earth Sciences and Physics) writes about using the Insight mission to detect seismic signals during the landing of Perseverance - the first time that anyone has tried using a spacecraft on the surface of another planet to detect another spacecraft arriving.

New machine learning system developed to identify deteriorating patients in hospital

Biomedical engineering Medical science Research

Researchers in Oxford have developed a machine learning algorithm that could significantly improve clinicians’ ability to identify hospitalised patients whose condition is deteriorating to the extent that they need intensive care.

Science Blog: From rust to riches? Computing goes green...or is that brown?

Computer science Physics Research

Professor Paolo Radaelli from Oxford’s Department of Physics, working with Diamond Light Source, has been leading research into silicon alternatives and his group’s surprising findings are published in Nature on 4th February.

Getting the message right on nature-based solutions to climate change

Climate change Research Zoology

Nature‐based solutions can play a key role in helping to tackle the climate and nature crises, while delivering other benefits for people, according to a new paper today from the Nature-based Solutions Initiative (NbSI) at the University of Oxford - but it is vital to get the message right about how to deliver successful NbS and avoid potential pitfalls.