A chemical radar allows bacteria to sense and eliminate predators.
Investigating how microorganisms communicate deepens our understanding of the complex ecological interactions that shape our environment is an area of key focus for the Cluster of Excellence “Balance of the Microverse.” A research team from the Cluster, based at the Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI) and Friedrich Schiller University Jena, has examined the interactions between amoebae, bacteria, and plants.
Researchers from the University of Bayreuth also contributed to the study. The findings pave the way for discovering new bioactive natural products.
The persistent plant pathogen and a single-celled organism with team spirit
The bacterium Pseudomonas syringae is a ubiquitous and devastating plant pathogen. The pathogen penetrates the plant via natural openings or injuries, infects it, and causes considerable damage in agriculture. Amoebae are natural enemies of the bacterium. The amoeba Polysphondylium pallidum, for instance, is a single-celled organism that feeds on bacteria.
However, if food becomes scarce, the unicellular organisms aggregate to form multicellular structures that allow for the generation and dispersal of spores. While not directly involved in the infection process of the plant, the amoeba is an important predator that forces the bacterium to evolve highly effective defense mechanisms in order to survive in their presence.
An amoeba kills itself
The research team led by Pierre Stallforth, professor at the University of Jena and head of department at the Leibniz-HKI, has now identified a previously unknown defense mechanism of Pseudomonas syringae.
“We were able to show how the bacterium uses a chemical radar to recognize and eliminate the hostile amoebae. Interestingly, the amoebae themselves play a crucial role in their own demise,” says Shuaibing Zhang, first author of the study.
Pierre Stallforth adds: “Pseudomonas syringae produces syringafactins. These are chemical compounds that are harmless to the amoeba, they enable the bacterium to move faster. When the amoeba encounters this molecule, the organism modifies syringafactin’s chemical structure. The bacterium in turn has a special sensor protein – the Chemical Radar Regulator (CraR) – which recognizes these modified molecules. This enables the bacteria to detect the presence of amoebae, whereupon genes responsible for the production of toxic substances – the pyrofactins – are activated. The pyrofactins in turn kill amoebae and, interestingly, are derivatives of the modified syringafactins.”
Defense mechanism provides opportunities for the development of new drugs
The infectivity of the bacterium is also linked to the chemical radar system: P. syringae can only infect thale cress, Arabidopsis thaliana, a very common plant model organism, in the presence of amoebae if the bacterium has an active “chemical radar” and is, therefore, able to defend itself against the predator.
The study provides valuable insights into the complex interplay between microorganisms, protozoa, and higher plants. It also provides starting points for the discovery of new bioactive natural substances that can be useful to humans as drugs or in pest control.
Reference: “A chemical radar allows bacteria to detect and kill predators” by Shuaibing Zhang, Kevin Schlabach, Victor Hugo Pérez Carrillo, Anan Ibrahim, Shahran Nayem, Anna Komor, Ruchira Mukherji, Somak Chowdhury, Lisa Reimer, Felix Trottmann, A. Corina Vlot, Christian Hertweck, Ute A. Hellmich and Pierre Stallforth, 2 April 2025, Cell.
DOI: 10.1016/j.cell.2025.02.033
Numerous fundings made this pioneering study possible under the direction of the Leibniz-HKI, including the Werner Siemens Foundation, the German Research Foundation within the Cluster of Excellence “Balance of the Microverse” and the ChemBioSys Collaborative Research Center. The states of Hessen and Thuringia also supported the project with funding from the European Regional Development Fund (EFRE).
News
Scientists Melt Cancer’s Hidden “Power Hubs” and Stop Tumor Growth
Researchers discovered that in a rare kidney cancer, RNA builds droplet-like hubs that act as growth control centers inside tumor cells. By engineering a molecular switch to dissolve these hubs, they were able to halt cancer [...]
Platelet-inspired nanoparticles could improve treatment of inflammatory diseases
Scientists have developed platelet-inspired nanoparticles that deliver anti-inflammatory drugs directly to brain-computer interface implants, doubling their effectiveness. Scientists have found a way to improve the performance of brain-computer interface (BCI) electrodes by delivering anti-inflammatory drugs directly [...]
After 150 years, a new chapter in cancer therapy is finally beginning
For decades, researchers have been looking for ways to destroy cancer cells in a targeted manner without further weakening the body. But for many patients whose immune system is severely impaired by chemotherapy or radiation, [...]
Older chemical libraries show promise for fighting resistant strains of COVID-19 virus
SARS‑CoV‑2, the virus that causes COVID-19, continues to mutate, with some newer strains becoming less responsive to current antiviral treatments like Paxlovid. Now, University of California San Diego scientists and an international team of [...]
Lower doses of immunotherapy for skin cancer give better results, study suggests
According to a new study, lower doses of approved immunotherapy for malignant melanoma can give better results against tumors, while reducing side effects. This is reported by researchers at Karolinska Institutet in the Journal of the National [...]
Researchers highlight five pathways through which microplastics can harm the brain
Microplastics could be fueling neurodegenerative diseases like Alzheimer's and Parkinson's, with a new study highlighting five ways microplastics can trigger inflammation and damage in the brain. More than 57 million people live with dementia, [...]
Tiny Metal Nanodots Obliterate Cancer Cells While Largely Sparing Healthy Tissue
Scientists have developed tiny metal-oxide particles that push cancer cells past their stress limits while sparing healthy tissue. An international team led by RMIT University has developed tiny particles called nanodots, crafted from a metallic compound, [...]
Gold Nanoclusters Could Supercharge Quantum Computers
Researchers found that gold “super atoms” can behave like the atoms in top-tier quantum systems—only far easier to scale. These tiny clusters can be customized at the molecular level, offering a powerful, tunable foundation [...]
A single shot of HPV vaccine may be enough to fight cervical cancer, study finds
WASHINGTON -- A single HPV vaccination appears just as effective as two doses at preventing the viral infection that causes cervical cancer, researchers reported Wednesday. HPV, or human papillomavirus, is very common and spread [...]
New technique overcomes technological barrier in 3D brain imaging
Scientists at the Swiss Light Source SLS have succeeded in mapping a piece of brain tissue in 3D at unprecedented resolution using X-rays, non-destructively. The breakthrough overcomes a long-standing technological barrier that had limited [...]
Scientists Uncover Hidden Blood Pattern in Long COVID
Researchers found persistent microclot and NET structures in Long COVID blood that may explain long-lasting symptoms. Researchers examining Long COVID have identified a structural connection between circulating microclots and neutrophil extracellular traps (NETs). The [...]
This Cellular Trick Helps Cancer Spread, but Could Also Stop It
Groups of normal cbiells can sense far into their surroundings, helping explain cancer cell migration. Understanding this ability could lead to new ways to limit tumor spread. The tale of the princess and the [...]
New mRNA therapy targets drug-resistant pneumonia
Bacteria that multiply on surfaces are a major headache in health care when they gain a foothold on, for example, implants or in catheters. Researchers at Chalmers University of Technology in Sweden have found [...]
Current Heart Health Guidelines Are Failing To Catch a Deadly Genetic Killer
New research reveals that standard screening misses most people with a common inherited cholesterol disorder. A Mayo Clinic study reports that current genetic screening guidelines overlook most people who have familial hypercholesterolemia, an inherited disorder that [...]
Scientists Identify the Evolutionary “Purpose” of Consciousness
Summary: Researchers at Ruhr University Bochum explore why consciousness evolved and why different species developed it in distinct ways. By comparing humans with birds, they show that complex awareness may arise through different neural architectures yet [...]
Novel mRNA therapy curbs antibiotic-resistant infections in preclinical lung models
Researchers at the Icahn School of Medicine at Mount Sinai and collaborators have reported early success with a novel mRNA-based therapy designed to combat antibiotic-resistant bacteria. The findings, published in Nature Biotechnology, show that in [...]
