Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Friends, Enemies Communicate With Plants in Similar Ways

23.02.2005


Two soil-dwelling strangers – a friend and a foe – approach a plant and communicate with it in order to enter a partnership. The friend wants to trade nitrogen for food. The foe is a parasite that wants to burrow in and harm the plant.


Fluorescence confocal microscope images of plant epidermal and root hair cells expressing Green Fluorescent Protein (GFP) fused with microtubule associated protein, MAP4 (left), and actin binding protein, Talin (right). New evidence confirms that root-knot nematodes and rhizobia produce an essentially identical cytoskeletal response in these tiny root hairs of L. japonicus.



In a new finding published in Proceedings of the National Academy of Sciences, researchers at North Carolina State University have found that the two strangers communicate with the plant in very similar ways. The plant’s responses to both friend and foe are also remarkably similar.

Using high-tech microscopy and florescent imaging techniques that allow for real-time, three-dimensional study in living cells over time, the NC State researchers discovered that the model legume Lotus japonicus responded similarly to signals from both rhizobia, the friends that fix nitrogen for the plant, and root-knot nematodes, the parasitic foes that want to harm the plant. Signals from both outsiders induce rapid changes in distribution of the plant’s cytoskeleton, which is part of a pathway that leads to a series of growth changes that include the formation of either nodules housing bacteria or giant cells from which the nematodes feed.


The scientists also discovered that, like rhizobia and contrary to popular belief, the root-knot nematode signals plants from a distance and therefore does not need to attach itself to the plant to elicit a response.

When the researchers studied L. japonicus plants missing the receptors that receive signals from other organisms – certain genes in the plant were modified to accomplish this – they discovered that the plants failed to respond to signals from both friend and foe, and therefore no changes were viewed in the plant’s cytoskeleton. “This exquisite system that plants have developed to allow beneficial interactions with other organisms like rhizobia is being exploited by nematodes,” says Dr. David Bird, associate professor of plant pathology, co-director of NC State’s Center for the Biology of Nematode Parasitism and co-author of the paper. “Nematodes have not only found a weak link in plants but may be using the very same bacterial machinery against it.”

The study started as a graduate research project of Ravisha R. Weerasinghe, the lead author of the paper, in the lab of Dr. Nina Allen, professor of botany and co-author of the paper. Weerasinghe first observed the changes in the plants triggered by signals from rhizobia, called Nod factors, and then saw the similar changes occurring when plants were signaled by root-knot nematodes. In the paper, the researchers call the nematodes’ signals “Nematode factors.”

After rhizobia perceive plant signals and send back Nod factors, the plant’s root hairs curl around the good bacteria. The rhizobia then migrate into the root and form special structures called nodules, where they turn atmospheric nitrogen into usable nitrogen for the plant and, in return, take some of the plant’s energy to survive. A similar relationship appeared when Weerasinghe studied the signals between plants and nematodes, even though the nematode provides no benefit to its host. Root-knot nematodes form feeding cells – so-called giant cells – in the plant and later galls or knots on it.

“We don’t know the precise structure of Nematode factor, but it appears that the nematodes may have actually acquired genes from rhizobia to exploit this signal pathway,” Bird says.

The research was funded by the National Science Foundation and the North Carolina Research Station.

Dr. Nina Allen | EurekAlert!
Further information:
http://www.ncsu.edu

More articles from Life Sciences:

nachricht Water world
20.11.2017 | Washington University in St. Louis

nachricht Carefully crafted light pulses control neuron activity
20.11.2017 | University of Illinois at Urbana-Champaign

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 “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Water world

20.11.2017 | Life Sciences

Less is more to produce top-notch 2D materials

20.11.2017 | Materials Sciences

Carefully crafted light pulses control neuron activity

20.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>