Featured Research

from universities, journals, and other organizations

How plants and bacteria 'talk' to thwart disease

Date:
November 27, 2009
Source:
University of California - Davis
Summary:
Unwrapping some of the mystery from how plants and bacteria communicate to trigger an innate immune response, scientists have identified the bacterial signaling molecule that matches up with a specific receptor in rice plants to ward off a devastating disease known as bacterial blight of rice.

Rice growing. Scientists have identified the bacterial signaling molecule that matches up with a specific receptor in rice plants to ward off a devastating disease known as bacterial blight of rice.
Credit: iStockphoto

When it comes to plants' innate immunity, like many of the dances of life, it takes two to tango. A receptor molecule in the plant pairs up with a specific molecule on the invading bacteria and, presto, the immune system swings into action to defend against the invasion of the disease-causing microbe.

Related Articles


Unwrapping some of the mystery from how plants and bacteria communicate in this dance of immunity, scientists at the University of California, Davis, have identified the bacterial signaling molecule that matches up with a specific receptor in rice plants to ward off a devastating disease known as bacterial blight of rice.

The researchers, led by UC Davis plant pathologist Pamela Ronald, will publish their findings in the Nov. 6 issue of the journal Science.

"The new discovery of this bacterial signaling molecule helps us better understand how the innate immune system operates," Ronald said.

"Because similar pairs of receptors and bacterial signaling molecules are known to exist not only in rice but also in other plants, as well as animals and humans, we are hopeful that this work will lead to new strategies for controlling diseases in plants and people," she said.

Disease resistance background

In 1995, Ronald's laboratory identified the XA21 gene, which produces a receptor protein that recognizes Xanthomonas oryzae pv. Oryzae, also known as Xoo, which causes bacterial blight disease. Xoo and other species of Xanthomonas infect virtually every crop species in the world.

Subsequent discoveries revealed that receptors with striking structural similarities to the XA21 receptor protein exist in other plants, flies, mice and even humans. These receptors were later named pattern recognition receptors or PRRs because they have the ability to recognize molecules that occur across species in a large class of disease-causing microbes. These receptors then can launch a protective immune defense on behalf of the plant or animal.

Together, the receptors (PRRs) and the microbial molecules they recognize comprise a previously unknown system of immunity called innate immunity. As the name suggests, this form of immunity is built into the genetic makeup of the plant, rather than developing over time with repeated exposure to disease-causing microbes. Unlike animals, plants do not produce antibodies.

The new findings

In their newly published study, Ronald and her colleagues identified a peptide -- a compound that they call ax21 -- as the molecule that binds with the XA21 receptor protein. The binding triggers a defense response against the bacterial disease.

The researchers note that ax21 is also found in many other species of Xanthomonas as well as in Xylella fastidiosa, a microbe that causes the devastating Pierce's disease in grapes. Furthermore, ax21 is even found in Stenotrophomonas maltophilia, a bacterium that causes respiratory tract infections in humans.

"These studies have led to a convergence in our understanding of the molecular mechanisms that govern how disease-causing microbes interact with the plants and animals they infect," Ronald said.

"We are hopeful that these discoveries will benefit agriculture and medicine in the United States and around the world by leading to development of treatments that will disrupt bacterial infection," she said.

Working with Ronald on this study were Sang-Won Lee, Sang-Wook Han, Malinee Sririyanum, Chang-Jin Park and Young-Su Seo, all researchers in the UC Davis Department of Plant Pathology.

Funding for the study was provided by the U.S. Department of Agriculture and by the National Institutes of Health.


Story Source:

The above story is based on materials provided by University of California - Davis. Note: Materials may be edited for content and length.


Cite This Page:

University of California - Davis. "How plants and bacteria 'talk' to thwart disease." ScienceDaily. ScienceDaily, 27 November 2009. <www.sciencedaily.com/releases/2009/11/091105143720.htm>.
University of California - Davis. (2009, November 27). How plants and bacteria 'talk' to thwart disease. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2009/11/091105143720.htm
University of California - Davis. "How plants and bacteria 'talk' to thwart disease." ScienceDaily. www.sciencedaily.com/releases/2009/11/091105143720.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins