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.

Signalling taking place between roots and rhizosphere bacteria

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

From The Conversation: Nocturnal dinosaurs: Night vision and superb hearing in a small theropod suggest it was a moonlight predator

Earth sciences Research

Roger Benson, Professor of Palaeobiology in the Department of Earth Sciences, and colleagues Lars Schmitz at Scripps College and Jonah Choiniere at the University of the Witwatersrand write about their new research into nocturnal dinosaurs.

Science Blog: Heatstroke: why the hotter the clock, the more accurate its timekeeping

Materials science Research

Dr Natalia Ares from the Department of Materials writes about a new study published in Physical Review X, in which for the first time she and colleagues have measured the entropy generated by a minimal clock.

Pea plants make smart investment decisions that could help inform sustainable agriculture

Plant sciences Research

Researchers in the Department of Plant Sciences have shown that pea plants are able to make smart investment decisions when it comes to interactions with their symbiotic bacterial partners. Better understanding of how plants manage these interactions could help with the move towards sustainable agriculture.

Science Blog: New water-based approach to manufacturing semiconductors

Materials science Research

With the increasing demand for high-tech devices such as smart phones, wearable watches and portable health monitoring devices, the semiconductor manufacturing industry faces a big challenge of fabricating these devices in a sustainable and cost-effective way.

Nature must be a partner, not just a provider of services

Research Zoology

Nature based Solutions (NbS) could support transformative change in environmental sustainability - to address major societal challenges, including the climate crisis - according to a new paper from Oxford researchers.

Rapid evolution and host immunity drive the rise and fall of antibiotic resistance during acute infection

Medical science Research Zoology

Antibiotic resistance poses a serious threat to human health, but how resistance emerges during infections remains poorly understood.

Similar stories

From The Conversation: Nocturnal dinosaurs: Night vision and superb hearing in a small theropod suggest it was a moonlight predator

Earth sciences Research

Roger Benson, Professor of Palaeobiology in the Department of Earth Sciences, and colleagues Lars Schmitz at Scripps College and Jonah Choiniere at the University of the Witwatersrand write about their new research into nocturnal dinosaurs.

Science Blog: Heatstroke: why the hotter the clock, the more accurate its timekeeping

Materials science Research

Dr Natalia Ares from the Department of Materials writes about a new study published in Physical Review X, in which for the first time she and colleagues have measured the entropy generated by a minimal clock.

Pea plants make smart investment decisions that could help inform sustainable agriculture

Plant sciences Research

Researchers in the Department of Plant Sciences have shown that pea plants are able to make smart investment decisions when it comes to interactions with their symbiotic bacterial partners. Better understanding of how plants manage these interactions could help with the move towards sustainable agriculture.

Science Blog: New water-based approach to manufacturing semiconductors

Materials science Research

With the increasing demand for high-tech devices such as smart phones, wearable watches and portable health monitoring devices, the semiconductor manufacturing industry faces a big challenge of fabricating these devices in a sustainable and cost-effective way.

Nature must be a partner, not just a provider of services

Research Zoology

Nature based Solutions (NbS) could support transformative change in environmental sustainability - to address major societal challenges, including the climate crisis - according to a new paper from Oxford researchers.

Rapid evolution and host immunity drive the rise and fall of antibiotic resistance during acute infection

Medical science Research Zoology

Antibiotic resistance poses a serious threat to human health, but how resistance emerges during infections remains poorly understood.