Featured Research

from universities, journals, and other organizations

History is key factor in plant disease virulence

Date:
April 21, 2012
Source:
National Science Foundation
Summary:
The virulence of plant-borne diseases depends on not just the particular strain of a pathogen, but on where the pathogen has been before landing in its host, according to new research results.

Close-up view of a tree affected by the disease.
Credit: Doug Schmidt

The virulence of plant-borne diseases depends on not just the particular strain of a pathogen, but on where the pathogen has been before landing in its host, according to new research results.

Related Articles


Scientists from the University of California System and the U.S. Department of Agriculture's Agricultural Research Service (USDA ARS) recently published the results in the journal PLoS ONE.

The study demonstrates that the pattern of gene regulation--how a cell determines which genes it will encode into its structure and how it will encode them--rather than gene make-up alone affects how aggressively a microbe will behave in a plant host.

The pattern of gene regulation is formed by past environments, or by an original host plant from which the pathogen is transmitted.

"If confirmed, this finding could add a key new dimension to how we look at microbes because their history is going to matter--and their history may be hard to reconstruct," said Matteo Garbelotto, an environmental scientist at the University of California, Berkeley and co-author of the paper.

Epigenetic factors--for example, gene regulation mechanisms controlled by diet or exposure to extreme environments--are well-known to affect the susceptibility of humans to some diseases.

The new study is the first to show a similar process for plant pathogens.

"Sudden oak death, for example, is one of many pathogens that seemingly came out of nowhere to ravage the forests of California," said Sam Scheiner, a director of the National Science Foundation's (NSF) Ecology and Evolution of Infectious Diseases (EEID) program, which funded the research.

"This study shows that such sudden emergence can happen through rapid evolution, and may provide clues for predicting future epidemics."

The EEID program is a joint effort of NSF and the National Institutes of Health. At NSF, it is supported by the Directorates for Biological Sciences and Geosciences.

Garbelotto said that other scientists hypothesized that gene regulation has an effect on plant pathogens, based on the evolutionary rates of portions of the genome that are known to have an effect on gene regulation.

"Our work provides the concrete evidence those hypotheses were correct," he said.

Researchers showed that genetically identical strains of the sudden oak death pathogen isolated from different plant hosts were strikingly different in their virulence and their ability to proliferate.

They also demonstrated that these traits were maintained long after they had been isolated from their hosts.

"We found that an identical strain placed in two different plant hosts will undergo distinct changes that will persistently affect the strain's virulence and fitness," said Takao Kasuga, a molecular geneticist with the USDA ARS and the lead author of the paper.

The implications for disease control are significant.

Scientists say that it may not be enough to know what strain of pathogens they are dealing with in order to make treatment decisions; it also may be necessary to know how the pathogen's genes are being regulated.

This study shows that gene regulation may be the result of the environments the strain inhabited before being identified.

Garbelotto uses a parallel example of a well-known human pathogen: particular strains of the H1N1 flu virus have been identified as highly virulent, so a diagnosis of one of these strains indicates to doctors that they should treat that flu aggressively.

"But, hypothetically, if you caught one of these aggressive strains of H1N1 from a guy that went to, for example, Paris, it could be 10 times more dangerous. You may never know from whom you got it, and it's even less likely that you'll be able to learn where your infector visited before passing the germ on to you."

In plants, Garbelotto said, tracking a pathogen's history may prove even more difficult.

Correct information could give scientists a new weapon to use against virulent strains of diseases like sudden oak death, which can devastate forests and the ecosystems that depend on them.

The researchers also identified two groups of genes that are capable of affecting virulence and whose expression patterns are indicative of the previous host species they inhabited.

Understanding the regulation of these genes may provide scientists with future approaches to control a disease, such as manipulating gene expression to artificially reduce the aggressiveness of plant pathogens.

While Garbelotto stresses that more study is needed, he says if the paper's findings are confirmed, it could influence not just treatment but policy as well.

"Most countries impose regulations on microbes based on their genetic make up--which ones can and can't cross state and international lines and how they must be transported," he said.

"Our findings suggest that when making regulatory policy, we may also need to identify gene expression levels and take into account the history of a microbe."

Co-authors of the paper include Melina Kozanitas and Daniel Huberli, also of UC Berkeley; Mai Bui of the USDA ARS; and David Rizzo, a plant pathologist at University of California, Davis.


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Journal Reference:

  1. Takao Kasuga, Melina Kozanitas, Mai Bui, Daniel Hόberli, David M. Rizzo, Matteo Garbelotto. Phenotypic Diversification Is Associated with Host-Induced Transposon Derepression in the Sudden Oak Death Pathogen Phytophthora ramorum. PLoS ONE, 2012; 7 (4): e34728 DOI: 10.1371/journal.pone.0034728

Cite This Page:

National Science Foundation. "History is key factor in plant disease virulence." ScienceDaily. ScienceDaily, 21 April 2012. <www.sciencedaily.com/releases/2012/04/120421203917.htm>.
National Science Foundation. (2012, April 21). History is key factor in plant disease virulence. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2012/04/120421203917.htm
National Science Foundation. "History is key factor in plant disease virulence." ScienceDaily. www.sciencedaily.com/releases/2012/04/120421203917.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