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 Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>