Navigation Links
History is key factor in plant disease virulence

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.

Scientists from the University of California System and the U.S. Department of Agriculture's Agricultural Research Service (USDA ARS) published the results today 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."


Contact: Cheryl Dybas
National Science Foundation

Related medicine news :

1. History of abandoned urban sites found stored in soil
2. Female cancer survivors have worse health behaviors than women with no cancer history
3. Lobular Breast Cancer Linked to Paternal Cancer History
4. Chronic post-traumatic stress disorder in women linked to history of rape, child abuse
5. Drinking Risky for Women With Family History of Breast Cancer: Study
6. Girls with family history of breast disease should avoid alcohol
7. More aggressive treatment not necessary for men with a family history of prostate cancer
8. Trastuzumab raises risk of heart problems in the elderly with history of heart disease or diabetes
9. Family history a risk factor for COPD
10. Family History May Predict Heart Attack More Than Stroke
11. Kids of Moms With History of Depression Seem Less Happy
Post Your Comments:
Related Image:
History is key factor in plant disease virulence
(Date:11/25/2015)... ... November 25, 2015 , ... Today, Mothers Against Drunk Driving ... dropped below 10,000 for the first time since 2011. In 2014, there were 9,967 ... data released by the National Highway Traffic Safety Administration (NHTSA), 32,675 people were killed ...
(Date:11/25/2015)... ... November 25, 2015 , ... "When I underwent breast reconstruction ... incredibly uncomfortable," said an inventor from Bronx, N.Y. "In order to meet my ... RECOVERY BRA for added comfort and support. The bra is easier to put ...
(Date:11/25/2015)... ... 25, 2015 , ... Many people know of the common symptoms of low ... dry skin. But many people who find their cholesterol levels and weight are creeping ... thyroid, especially if they don’t have any of the other symptoms. , Thyroid hormone ...
(Date:11/25/2015)... ... November 25, 2015 , ... Students and parents have something ... winners of the Create Real Impact awards. California Casualty is proud to ... the tide of distracted and reckless driving, the number one killer of young drivers. ...
(Date:11/24/2015)... (PRWEB) , ... November 24, 2015 , ... ... certified to offer their patients the many benefits of the revolutionary BIOLASE WaterLase ... sharp cutting and scraping tools traditionally used by a dentist in Gettysburg, ...
Breaking Medicine News(10 mins):
(Date:11/24/2015)... 24, 2015   HeartWare International, Inc . (NASDAQ: ... circulatory support technologies that are revolutionizing the treatment of ... Executive Officer Doug Godshall is scheduled to ... Healthcare Conference on December 1, 2015 at 3:00 p.m. ... New York . ...
(Date:11/24/2015)... LAUSANNE and BERN, Switzerland ... SA, the ARTORG Center for Biomedical Engineering Research of ... and the Division of Endocrinology, Diabetes and Clinical Nutrition ... announce the start of an exclusive collaboration to develop ... control algorithm for the personalised delivery of insulin for ...
(Date:11/24/2015)... 2015 F1000Workspace - a research ... it was launched just six months ago. --> ... platform for scientists - since it was launched just six ... loaded on to F1000Workspace - a research collaboration, ... was launched just six months ago. --> ...
Breaking Medicine Technology: