Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Critical early-defense trigger in plants found

16.05.2003


The gene for an enzyme that is key to natural disease resistance in plants has been discovered by biologists at the Boyce Thompson Institute for Plant Research (BTI) and at Cornell University. The researchers say that by enhancing the activity of the enzyme they might be able to boost natural disease resistance in crop plants without resorting to pesticides or the introduction of non-plant genes.

The research, reported in the latest (May 16) issue of the journal Cell , describes the discovery of the gene that codes for an enzyme (a protein that carries out a chemical reaction) that is activated when a plant senses it is being attacked by a pathogen. When activated, the enzyme produces nitric oxide (NO), a hormone that tells the plant to turn on its defense arsenal.

According to plant pathologist Daniel F. Klessig, lead author of the Cell paper and president of BTI, located on the Cornell campus, the discovery provides a new understanding of the biochemical and genetic pathways in plants that enable them to protect themselves from disease.



"It’s known that the hormone nitric oxide plays an important role in immunity in plants as well as in humans and other animals," says Klessig. "But the enzyme responsible for its production in plants was unknown until now. With this discovery, we may be able to modify plants so that they produce nitric oxide more quickly, or in larger amounts, when they are attacked by a disease-causing pathogen, enabling them to better protect themselves from invaders."

Authors of the Cell paper, "The Pathogen-Inducible Nitric Oxide Synthase (iNOS) in Plants is a Variant of the P Protein of the Glycine Decarboxylase Complex," also include Meena Chandok, a BTI senior research associate; Anders Jimmy Ytterberg, Cornell doctoral candidate in plant biology; and Klaas J. van Wijk, Cornell assistant professor of plant biology.

"This discovery really is a surprise because the plant enzyme looks very different from mammalian nitric oxide-synthesizing enzymes,"said Brian Crane, Cornell assistant professor of chemistry and chemical biology. Crane now is working with Klessig and Chandok to determine the three-dimensional structure of the protein that will lead biologists to understand its chemical mechanism.

The discovery is significant, the researchers note, because NO is a critical early-warning signal to the plant that it needs to activate its immune response. The difficulty inherent in the research, according to Klessig, was that the plant’s NO-producing enzyme has a completely different sequence than enzymes with similar activity found in all animals. The new research suggests, he says, that the chemistry the plant and animal enzymes use to produce NO also is different.

These differences, Klessig says, could provide clues concerning the way the animal enzyme works, which, in turn, could lead to improved treatment of human diseases by enhancing the activity of the enzyme.

"Part of the success of the green revolution depends on the use of chemical-based fungicides and other pesticides to protect crops against microbial pathogens and insects," says Klessig. "An alternative strategy to protect crops utilizes a plant’s own natural defenses. An approach in which plant molecular biologists have overproduced plant proteins with antimicrobial activity, such as PR proteins or defensin, has met with only limited success to date, perhaps because only a small portion of the defense arsenal is involved.

"Our discovery of the enzyme that produces the critical early-defense signal, NO, means that we now may be able to regulate the production of this signal.

The turning up of this signal should lead to the turning on of a large portion of the defense arsenal. The end result could be crop plants that can better ward off disease without the use of potentially harmful fungicides and other pesticides, or the introduction of non-plant genes."

Van Wijk, whose research group identified the protein by tandem mass spectrometry, stresses that without the availability of the very sensitive mass spectrometry instruments and the plant genome information "we would not have been able to find this."

The Boyce Thompson Institute was opened in 1924 and is an independent, not-for-profit plant research organization. BTI funding for the Cell research was provided, in part, by a Plants and Human Health Grant from the Triad Foundation.

David Brand | Cornell News
Further information:
http://bti.cornell.edu
http://www.cell.com
http://www.news.cornell.edu/releases/May03/NewGeneKlessig.html

More articles from Life Sciences:

nachricht Ambush in a petri dish
24.11.2017 | Friedrich-Schiller-Universität Jena

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

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...

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

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>