Volume 90 Issue 26 | p. 39 | Concentrates
Issue Date: June 25, 2012

Rice Pathogen’s Trick Revealed

Fungus grows a big club appendage to blast its way into rice cells
Department: Science & Technology
News Channels: Biological SCENE
Keywords: plant pathogen, rice, fungus, blast fungus, pesticide
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A side view of the rice blast fungus’s peg, after penetrating into a rice cell.
Credit: Courtesy of Nicholas Talbot
A rice blast fungus infects a rice cell.
 
A side view of the rice blast fungus’s peg, after penetrating into a rice cell.
Credit: Courtesy of Nicholas Talbot
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Credit: Courtesy of Nicholas Talbot
An image of a rice blast fungus.
 
Credit: Courtesy of Nicholas Talbot

About 30% of the worldwide rice crop— enough food for 60 million people—is lost annually to a fungus called Magnaporthe oryzae. Now, researchers have figured out how the pathogen, known as the rice blast fungus, infects its prey (Science, DOI: 10.1126/science.1222934). When it’s time to infect, the fungus begins to grow an enormous batlike appendage called an appressorium, which it rams through a rice plant’s cell wall to gain entry. Yasin F. Dagdas and Nicholas J. Talbot of the University of Exeter, in England, led the work to find out which protein structures within the appressorium supply the right shape and rigidity to allow the fungal peg to blast into a rice cell. They found that cytoskeleton proteins called septins polymerize into a toroidal ring to channel the pressure for the penetration peg. “We’ve never seen rings like that in other organisms,” Dagdas says. Because septins are not found in plants, a pesticide that targets these proteins or their polymerization might be an effective treatment and unlikely to hurt the rice. However, septins are found in other organisms, including humans, so any treatments would have to be made specific to the fungus’s septins.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society

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