Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UNC plant researchers discover proteins interact to form hair-trigger protection against invaders

27.06.2005


Experimenting with Arabidopsis, a fast-growing cousin of the humble mustard plant, scientists at the University of North Carolina at Chapel Hill got a big surprise while investigating how plants respond to attacks from disease organisms such as bacteria and viruses.



"Contrary to what we thought we’d find, our experiments showed that at least three different proteins work in concert with one another in tug-of war or teeter totter-fashion to keep plant defenses in a state of constant readiness," said Dr. Jeffrey L. Dangl, John N. Couch professor of biology in UNC’s College of Arts and Sciences.

Previously, he and others believed that the proteins -- RAR1, SGT1 and HSP90 -- were required for what is called signal transduction -- relaying like Paul Revere the message that an enemy had arrived, Dangl said. Instead, they are needed to form an even earlier disease surveillance antenna or hair trigger. When disease invaders pull that trigger, infected plants cells quickly commit suicide, often preventing the invader from destroying the entire plant.


The new discovery appears to be a universal mechanism for defense by all plants against not only bacteria and viruses, but also parasitic fungi, insects and worms, he said.

"This work is important because every year, these organisms cause us to lose some 30 percent of our grain, fruit and vegetable crops after all the human, water and soil energy has already gone into producing them," Dangl said. "The hope is that we might be able to manipulate plants’ immune systems to make them more resistant to pathogens using fewer expensive and polluting chemicals."

A report on the findings appears in this week’s edition (June 24) of Science Express, the online, early-release version of the journal Science. Other authors are postdoctoral fellow Dr. Ben F. Holt III and Ph.D. student Youssef Belkhadir, both in biology.

"Plants use resistance proteins to defend themselves against pathogen attack by initiating a defense response," Holt said. "The proteins RAR1, HSP90 and SGT1 were previously thought to work together to help resistance proteins in this function. To our surprise, we found that SGT1 can actually work against, or antagonize, the other two proteins to disable resistance protein function."

The researchers also showed why they antagonized each other, he said. RAR1 and HSP90 can prevent resistance proteins from disappearing, while SGT1 helps them disappear. The result is that the system remains poised for an immediate response to bacteria and other attackers.

"By controlling disappearance of resisting proteins, RAR1, HSP90 and SGT1 control whether or not the plant is about to recognize that it is under pathogen attack," Holt said. "So the emerging story is that RAR1 and HSP90 keep resistance proteins ready to perceive pathogen signals, and SGT1 probably pulls against these two to send resistance proteins to their destruction."

The National Science Foundation supported the research through its Arabidopsis 20-10 Project, which aims to describe the functions of all 28,000 genes in the model plant.

Scientists study Arabidopsis, also known as thale cress or mouse-eared cress, because it is small and can produce five to six generations a year rather than just one or two like most crop plants. That rapid reproduction allows them to study the plant’s genetics faster than they could with other species.

Understanding Arabidopsis completely will teach scientists an enormous amount about all other flowering plants, which are closely related genetically, Dangl said. The new genomics technology, developed by Patrick Brown and David Botstein at Stanford University, has been applied to yeast, fruit flies and humans but not to plants in a large, systematic way. Arabidopsis was the first plant for which scientists succeeded in mapping its entire genetic composition.

Dangl is also with UNC’s Curriculum in Genetics, Department of Microbiology and Immunology and Carolina Center for Genome Sciences.

David Williamson | EurekAlert!
Further information:
http://www.unc.edu

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>