Researchers examine bacterial rice diseases, search for genetic solutions

Apr 01, 2009

As a major food source for much of the world, rice is one of the most important plants on earth.

Keeping it safe from disease has become, in part, the task of a group of three researchers from Iowa State University and one from Kansas State University.

The researchers are looking at two bacterial diseases of . The most costly is bacterial blight of rice, which is caused by a bacterium called Xanthomonas oryzae pathovar oryzae, and can diminish yield by up to 50 percent.

"This is the most important bacterial disease in rice, and in some areas, it is the most important rice disease of any kind," said Adam Bogdanove, an associate professor of plant pathology who is part of the ISU research team.

The team is also studying bacterial leaf streak of rice caused by the closely related bacterium Xanthomonas oryzae pathovar oryzicola. Bacterial leaf streak is usually not as damaging as bacterial blight, but it is increasing in importance in many areas of the world, particularly Southeast Asia.

These bacteria damage rice by entering the plant and taking control of certain rice cell processes, eventually killing the rice cells. Pathovar oryzae does this in the vascular system of the plant, which typically allows the bacterium to spread faster and cause more damage than is its cousin, oryzicola, which is limited to growth in the tissue between the veins.

Some types of rice are naturally resistant to the Xanthomonas bacteria. Bogdanove and other researchers -- Bing Yang, Iowa State assistant professor of genetics development and cell biology; Dan Nettleton, Iowa State professor of statistics; and Frank White, principal investigator and professor of plant pathology at Kansas State University, Manhattan -- are researching why some types of rice are naturally resistant to the bacteria.

In rice varieties that are resistant to the diseases, the team is exposing the plants to the two bacteria. They then check to see which plant are activated, and to what extent.

By identifying which genes are turned on, Bogdanove believes the team can identify the genes that are making the plants resistant.

"We are looking at genes of successful plants," he said. "What genes are active and when and how much they are being turned on."

Bogdanove hopes that this effort will aid in breeding the resistance into cultivated varieties that are currently susceptible to the diseases.

Another aspect of the research is aimed at discovering how the bacteria change gene expression in susceptible rice plants.

"If we understand which genes are being manipulated by the pathogens in disease, we can look into different varieties and wild relatives of rice for variants of these genes that are immune to manipulation and bring these genes into cultivated varieties," said Bogdanove. "The idea is to reduce or eliminate susceptibility altogether."

Rice is the major food staple for more than half the world's population. In the United States, rice is planted on almost 3 million acres with yields of around 7,000 pounds per acre in 2007, according the U.S. Department of Agriculture.

American producers grow 95 percent of the rice eaten in this country and the United States is a major exporter as well, according to Bogdanove.

In addition to the benefits to rice, the research should be helpful in understanding and controlling diseases in other cereal crops.

"Rice is a model plant for cereal biology," said Bogdanove.

Source: Iowa State University

Explore further: Orchid named after UC Riverside researcher

add to favorites email to friend print save as pdf

Related Stories

Transplanted corn gene protects rice

Oct 18, 2005

Kansas State University scientists say they've demonstrated resistance to bacterial streak disease in maize can be transferred to rice.

Gene's past could improve the future of rice

Jan 23, 2009

(PhysOrg.com) -- In an effort to improve rice varieties, a Purdue University researcher was part of a team that traced the evolutionary history of domesticated rice by using a process that focuses on one gene.

USDA approves rice with human genes

Mar 07, 2007

A California biotechnology company has been given preliminary approval by U.S. Agriculture Department to plant rice that contains human genes.

Genomics Research Focuses on Rice Variety Improvement

Jul 01, 2008

Crop varieties can be improved through the study of genomics without creating genetically transformed varieties. That is the mission of a multistate research project led by the University of Arkansas System’s Division of ...

Recommended for you

Orchid named after UC Riverside researcher

10 hours ago

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

12 hours ago

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

12 hours ago

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 0

More news stories

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...