How soil dwelling bacteria adapt to richer or poorer conditions

June 29, 2017, John Innes Centre
Rosaria Campilongo - John Innes Centre Scientist. Credit: John Innes Centre

Scientists have identified a unique mechanism that the soil dwelling bacterium Pseudomonas fluorescens uses to effectively exploit nutrients in the root environment.

The breakthrough offers multiple new applications, according to the team of John Innes Centre scientists behind the discovery: for the study of human pathogens, for , and for the productions of biosensors which help detect biological changes in and their environment.

P. fluorescens is a common soil bacteria that colonises plant roots, entering into a "marriage of convenience," where it improves plant health in return for exuded nutrients from the plant.

The team at the John Innes Centre, Norwich, showed how the "twin" transcriptional factors HexR and RccR can remodel central in P. fluorescens, enabling the bacterium to adapt to its surroundings.

The paper, titled "One ligand, two regulators and three binding sites: how KDPG controls primary carbon metabolism in Pseudomonas" is published in the Journal PLOS Genetics. The study provides a fundamental new insight into how bacteria tune their metabolic responses to available nutrients.

In particular, the RccR protein employs a unique and sophisticated two-way switch that enables it to simultaneously suppress and activate the expression of different genes.

Dr Jacob Malone, a project leader at the John Innes Centre said: "The RccR protein functions in a completely different way to conventional regulators of this type. Virtually every regulator we know of operates via an on-off switch – it either binds to DNA or it doesn't. RccR on the other hand uses an either-or switch. The principles underpinning RccR function make it an incredible tool for use as a biosensor, and have lots of potential for use in synthetic biology and the production of a new generation of genetic circuits."

The study not only explains how P. fluorescens adapts its metabolism to exploit nutrients secreted by plant roots, but it also suggests medical applications.

The report co-author Rosaria Campilongo, a research assistant at the John Innes Centre, explained how her findings can be applied to the study of the human pathogen Pseudonomas aeruginosa, a major factor in cystic fibrosis lung infection: "The RccR system is shared by all Pseudomonas species, including . This means that characterising RccR in P. fluorescens may open new insights into the pathogenesis and potential treatment of P. aeruginosa."

Explore further: 'Exciting biology' uncovers plants' high-fat diet for fungal benefactors

More information: Rosaria Campilongo et al. One ligand, two regulators and three binding sites: How KDPG controls primary carbon metabolism in Pseudomonas, PLOS Genetics (2017). DOI: 10.1371/journal.pgen.1006839

Related Stories

Scientists disable infectious bacteria by removing key protein

February 4, 2016

Scientists at the John Innes Centre and the University of East Anglia have made an exciting discovery that could provide a new way to prevent bacterial infections in both humans and plants without triggering multi-drug resistance ...

Wheat choice has lasting effect on soil health and yield

October 6, 2015

Scientists investigating how to control take-all, a fungus that lives in soil and infects wheat roots to cause disease, have discovered that different varieties of wheat have distinct and lasting impacts on the health of ...

Recommended for you

How leaves talk to roots

September 26, 2018

New findings show that a micro RNA from the shoot keeps legume roots susceptible to symbiotic infection by downregulating a gene that would otherwise hinder root responses to symbiotic bacteria. These findings reveal what ...

Microbial dark matter dominates Earth's environments

September 26, 2018

Uncultured microbes—those whose characteristics have never been described because they have not yet been grown in a lab culture—could be dominating nearly all the environments on Earth except for the human body, according ...

Team names world's largest ever bird—Vorombe titan

September 25, 2018

After decades of conflicting evidence and numerous publications, scientists at international conservation charity ZSL's (Zoological Society of London) Institute of Zoology, have finally put the 'world's largest bird' debate ...

The grim, final days of a mother octopus

September 25, 2018

Octopuses are the undisputed darlings of the science internet, and for good reason. They're incredibly intelligent problem-solvers and devious escape artists with large, complex nervous systems. They have near-magical abilities ...

Climate change not main driver of amphibian decline

September 25, 2018

While a warming climate in recent decades may be a factor in the waning of some local populations of frogs, toads, newts and salamanders, it cannot explain the overall steep decline of amphibians, according to researchers.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.