Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plant immune system detects bacteria through small fatty acid molecules How plants defend themselves

12.04.2019

Like humans and animals, plants defend themselves against pathogens with the help of their immune system. But how do they activate their cellular defenses? Researchers at the Technical University of Munich (TUM) have now discovered that receptors in plant cells identify bacteria through simple molecular building blocks.

"The immune system of plants is more sophisticated than we thought," says Dr. Stefanie Ranf from the Chair of Phytopathology of the TU Munich. Together with an international research team, the biochemist has discovered substances that activate plant defense.


Dr. Stefanie Ranf tests whether mature plants with a mutation in the LORE gene are more susceptible to infection with pathogenic bacteria.

Image: A. Eckert / TUM


Arabidopsis thaliana leaves are infected by simply pressure-infiltrating a solution containing the bacteria.

Image: A. Eckert / TUM

Until now, scientists have thought that plant cells – similar to those of humans and animals – recognize bacteria through complex molecular compounds, for example from the bacterial cell wall. In particular, certain molecules composed of a fat-like part and sugar molecules, lipopolysaccharides or LPS for short, were suspected of triggering an immune response.

In 2015, Ranf's team successfully identified the respective receptor protein: lipo-oligosaccharide-specific reduced elicitation, or LORE for short. All experiments indicated that this LORE protein activates the plant cell's immune system when it detects LPS molecules from the cell wall of certain bacteria.

A throwback leads to the right track

"The surprise came when we wanted to study this receptor protein more closely," recalls Ranf. "Our goal was to find out how LORE distinguishes different LPS molecules. For this we needed high-purity LPS. "

The researchers found that only LPS samples with certain short fatty acid constituents triggered plant defense. Surprisingly, they found in all these active LPS samples also extremely strong adhering free fatty acid molecules. Only after months of experimentation was the team able to separate these free fatty acids from the LPS.

"When we finally succeeded in producing highly purified LPS, it became apparent that the plant cell did not respond to them at all! Thus, it was clear that the immune response is not triggered by LPS, but instead by these short fatty acids" said Ranf.

Targeting bacteria building blocks

The 3-hydroxy fatty acids are very simple chemical building blocks compared to the much larger LPS. They are indispensable for bacteria and are produced in large quantities for incorporation into diverse cellular components.

"The strategy of plant cells to identify bacteria through these basic building blocks is extremely sophisticated; the bacteria require these 3-hydroxy fatty acids and therefore cannot bypass the immune response," summarizes Ranf.

Fitness program for plants

In the future, these results could help in breeding or genetically engineering plants with an improved immune response. It is also conceivable that plants treated with 3-hydroxy fatty acids would have increased resistance to pathogens.

More information:

The work was performed by an international and interdisciplinary collaboration of plant molecular biologists, chemists, and microbiologists. In addition to the Chair of Phytopathology and the Chair of Food Chemistry and Molecular Sensory Science of TUM, the Research Center Borstel (Leibniz Lung Center), the Helmholtz Zentrum München, the Austrian Gregor Mendel Institute for Molecular Plant Biology, the University of Maryland / USA, and the French University of Reims Champagne-Ardenne were involved in this work.

Stefanie Ranf’s research was funded by the German Research Foundation (DFG) as part of the Collaborative Research Center (SFB) 924 and the Emmy Noether Program.

Wissenschaftliche Ansprechpartner:

Dr. Stefanie Ranf
Technical University of Munich
Ranf-Lab at Chair of Phytopathology
Emil-Ramann-Str. 2, 85354 Freising, Germany
Tel.: +49 8161 71 5626 – E-mail: stefanie.ranf@tum.de

Originalpublikation:

Bacterial medium chain 3-hydroxy fatty acid metabolites trigger immunity in Arabidopsis plants
Alexander Kutschera, Corinna Dawid, Nicolas Gisch, Christian Schmid, Lars Raasch, Tim Gerster, Milena Schäffer, Elwira Smakowska-Luzan, Youssef Belkhadir, A. Corina Vlot, Courtney E. Chandler, Romain Schellenberger, Dominik Schwudke, Robert K. Ernst, Stéphan Dorey, Ralph Hückelhoven, Thomas Hofmann, Stefanie Ranf
Science, April 12, 2019 – DOI: 10.1126/science.aau1279
Link: https://science.sciencemag.org/cgi/doi/10.1126/science.aau1279

Weitere Informationen:

https://www.tum.de/nc/en/about-tum/news/press-releases/detail/article/35335/ Link to the press release

Dr. Ulrich Marsch | Technische Universität München

More articles from Life Sciences:

nachricht Protein complex may help prevent neurodegenerative diseases
12.04.2019 | Universität Konstanz

nachricht CD30 – from witness to culprit
12.04.2019 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A long-distance relationship in femtoseconds

Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.

Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...

Im Focus: Researchers 3D print metamaterials with novel optical properties

Engineers create novel optical devices, including a moth eye-inspired omnidirectional microwave antenna

A team of engineers at Tufts University has developed a series of 3D printed metamaterials with unique microwave or optical properties that go beyond what is...

Im Focus: Newly discovered mechanism of plant hormone auxin acts the opposite way

Auxin accumulation at the inner bend of seedling leads to growth inhibition rather than stimulation as in other plant tissues.

Increased levels of the hormone auxin usually promote cell growth in various plant tissues. Chinese scientists together with researchers from the Institute of...

Im Focus: Creating blood vessels on demand

Researchers discover new cell population that can help in regenerative processes

When organs or tissues are damaged, new blood vessels must form as they play a vital role in bringing nutrients and eliminating waste. This is the only way for...

Im Focus: Substantial differences between the tumor-promoting enzymes USP25 and USP28 identified

Researchers from the Rudolf Virchow Center of the University of Würzburg (JMU) have solved the structures of the cancer-promoting enzymes USP25 and USP28 and identified significant differences in their activities. Both enzymes promote the growth of various tumors. The results were published in the journal Molecular Cell and could benefit towards the development of new, low-side-effects anticancer drugs.

The permanent interplay of protein production and degradation is a major driver of cellular metabolism. A key mechanism of this regulation is the labeling of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

European Geosciences Union meeting: ExoMars press conference, live streams, on-site registration

02.04.2019 | Event News

Networks make it easier

02.04.2019 | Event News

 
Latest News

CD30 – from witness to culprit

12.04.2019 | Life Sciences

Agrophotovoltaics: High Harvesting Yield in Hot Summer of 2018

12.04.2019 | Power and Electrical Engineering

ESJET printing technology for large area active devices awarded

11.04.2019 | Awards Funding

VideoLinks
Science & Research
Overview of more VideoLinks >>>