Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Agent that triggers immune response in plants is uncovered

08.10.2007
Although plants lack humans' T cells and other immune-function cells to signal and fight infection, scientists have known for more than 100 years that plants still somehow signal that they have been attacked in order to trigger a plantwide resistance.

Now, researchers at the Boyce Thompson Institute for Plant Research (BTI) on the Cornell campus have identified the elusive signal in the process: methyl salicylate, an aspirin-like compound that alerts a plant's immune system to shift into high gear.

This phenomenon is called systemic acquired resistance and is known to require movement of a signal from the site of infection to uninfected parts of the plant.

The findings are published in the Oct. 5 issue of Science.

"By finally identifying a signal that moves from an infection site to activate defenses throughout the plant, as well as the enzymes that regulate the level of this signal, we may be in a position to alter the signal in a way that enhances a plant's ability to defend itself," said BTI senior scientist Daniel F. Klessig, an adjunct professor in plant pathology at Cornell, who conducted the work with Sang-Wook Park and other BTI colleagues.

Their approach, using gene technology to enhance plant immunity, could have wide consequences, boosting crop production and reducing pesticide use.

Methyl salicylate is a modified form of salicylic acid (SA), which has been used for centuries to relieve fever, pain and inflammation, first through the use of willow bark and, since 1889, with aspirin, still the most widely used drug worldwide.

In the 1990s, Klessig's research group reported that SA and nitric oxide are two critical defense-signaling molecules in plants, as well as playing important roles in human health. Then, in 2003 and 2005, the group reported in the Proceedings of the National Academy of Sciences that an enzyme, salicylic acid-binding protein 2 (SABP2), is required for systemic acquired resistance and converts methyl salicylate (which is biologically inactive as it fails to induce immune responses) into SA, which is biologically active.

After plants are attacked by a pathogen, the researchers had previously found, they produce SA at the infection site to activate their defenses. Some of the SA is converted into methyl salicylate, which can be converted back into SA by SABP2.

Using plants in which SABP2 function was either normal, turned off or mutated in the infected leaves or the upper, uninfected leaves, Klessig's group showed that SABP2 must be active in the upper, uninfected leaves for systemic acquired resistance to develop properly. By contrast, SABP2 must be inactivated in the infected leaves by binding to SA.

"This inactivation allows methyl salicylate to build up," explained Klessig. "It then flows through the phloem (or food-conducting "tubes") to the uninfected tissue, where SABP2 converts it back into active SA, which can now turn on the plant's defenses."

Klessig said that it is unclear why plants send this hormone to uninfected tissue in an inactive form, which then must be activated by removal of the methyl group.

"This research also provides insight into how a hormone like SA can actively regulate its own structure -- and thereby determine its own activity -- by controlling the responsible enzyme," noted Park, the lead author of the paper.

Blaine Friedlander | EurekAlert!
Further information:
http://www.cornell.edu

Further reports about: SABP2 immune methyl methyl salicylate resistance salicylate

More articles from Life Sciences:

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

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 quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>