Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Blunting rice disease

03.06.2014

UD researchers aim to disarm a 'cereal killer'

A fungus that kills an estimated 30 percent of the world’s rice crop may finally have met its match, thanks to a research discovery made by scientists at the University of Delaware and the University of California at Davis.


UD researchers Harsh Bais, Carla Spence (left) and Nicole Donofrio examine rice plants. They have identified a naturally occurring microbe in soil that inhibits the devastating rice blast fungus.

The research team, led by Harsh Bais, associate professor of plant and soil sciences in UD’s College of Agriculture and Natural Resources, has identified a naturally occurring microbe living right in the soil around rice plants — Pseudomonas chlororaphis EA105 — that inhibits the devastating fungus known as rice blast. What’s more, the beneficial soil microbe also induces a system-wide defense response in rice plants to battle the fungus.

The research, which is funded by the National Science Foundation, is published in BMC Plant Biologyand includes, along with Bais, authors Carla Spence, a doctoral student in the Department of Biological Sciences, Emily Alff, who recently earned her master’s degree in plant and soil sciences, and Nicole Donofrio, associate professor of plant and soil sciences, all from UD; and SundaresanVenkatesan, professor, Cameron Johnson, assistant scientist, and graduate student Cassandra Ramos, all from UC Davis. 

“We truly are working to disarm a ‘cereal killer’ and to do so using a natural, organic control,” says Bais, in his laboratory at the Delaware Biotechnology Institute. In addition to rice, a distinct population of the rice blast fungus also now threatens wheat production worldwide.

“Rice blast is a relentless killer, a force to be reckoned with, especially as rice is a staple in the daily diet of more than half the world’s population — that’s over 3 billion people,” Bais notes. “As global population continues to grow, biocontrol bacteria may be an important key for farmers to overcome crop losses due to plant disease and to produce more food from the same acre of land.”

According to Bais, the rice blast fungus (Magnaporthe oryzae) attacks rice plants through spores resembling pressure plugs that penetrate the plant tissue. Once these spores infiltrate the cell wall, the fungus “eats the plant alive,” as Bais says. Common symptoms of rice blast are telltale diamond shaped-lesions on the plant leaves.

In order to do its work, the spore must produce a structure called the appressorium, a filament that adheres to the plant surface like an anchor. Without it, the fungus can’t invade the plant.

In a research study published in the journal Planta this past October, Bais and colleagues Spence, Donofrio and Vidhyavathi Raman showed that Pseudomonas chlororaphis EA105 strongly inhibited the formation of the appressorium and that priming rice plants with EA105 prior to infection by rice blast decreased lesion size.

For her work, Spence, the lead author, recently received the Carson Best Paper Award for the best scientific paper published by a Ph.D. student in biological sciences at UD. 

The next step in the research was to sample the rhizosphere, the soil in the region around the roots of rice plants growing in the field, to reveal the microbial community living there and to attempt to elucidate their roles.

Thanks to DNA sequencing techniques, Bais says that identifying the various microorganisms in soil is easy. But understanding the role of each of those microorganisms is a continuing story.

A natural control for a deadly fungus

“Everyone knows what’s there, but we don’t know what they are doing,” Bais says of the microbes. To home in on the source of the antifungal impact, Bais and his colleagues are relying on what he refers to as “old school culturing” to find out if a single bacterium or a group of different bacteria are at work.

In their study reported in BMC Plant Biology, the researchers used gene sequencing techniques to identify 11 naturally occurring bacteria isolated from rice plants grown in the field in California. These bacteria were then tested in the laboratory, with Pseudomonas chlororaphis EA105 demonstrating the strongest impact on rice blast. The soil microbe reduced the formation of the anchor-like appressoria by nearly 90 percent while also inhibiting fungal growth by 76 percent. 

Bais points out that although hydrogen cyanide is commonly produced by pseudomonad bacteria, the antifungal impact of Pseudomonas chlororaphis EA105 appears to be independent of cyanide production. 

Applying a natural soil microbe as an antifungal treatment versus chemical pesticides offers multiple benefits to farmers and the environment, Bais says. 

“Rice blast quickly learns how to get around synthetics — most manmade pesticides are effective only for about three years,” Bais says. “So it’s really cool to find a biological that can attenuate this thing.” 

Bais, who also has conducted multiple studies with beneficial microbes in the Bacillus family, envisions a day when farmers will treat plants with a “magic cocktail of microbes” naturally found in soil to help boost their immunity and growth. 

This summer, he and his colleagues will conduct field trials using Pseudomonas chlororaphis EA105 on rice plants grown on the UD farm. He also will work with farmers in the central states in India.

The research is supported by a $1.9 million grant from the National Science Foundation’s Plant Genome Research Project.

Article by Tracey Bryant

Photo by Kathy F. Atkinson

Donna O'Brien | Eurek Alert!
Further information:
http://www.udel.edu/udaily/2014/may/microbe-rice-blast-052714.html

Further reports about: BMC Bais Delaware Pseudomonas antifungal bacteria farmers formation fungus microbe microbes pesticides spores

More articles from Life Sciences:

nachricht World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes
17.07.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>