A study released by campus biochemists could lead to new fungicides and better protection of rice crops.
Led by Michael Marletta, campus professor of chemistry and molecular and cell biology, the team of researchers discovered how the fungus Magnaporthe Oryzae enters rice plants and causes rice blast disease.
“Berkeley is filled with examples of basic fundamental research that leads to important applications in society,” Marletta said in an email. “We discovered an important aspect of how the fungus gains entry to the plant. If you can stop this, you will save the plant.”
According to Marletta, the amount of rice lost annually due to rice blast disease could feed 60 million additional people.
Richard Sayler, a postdoctoral associate involved in the study, said that the team’s research discovered how M. Oryzae is able to invade rice plants.
“Our study characterized an enzyme that’s important for the infection of the fungus Magnaporthe Oryzae on rice plants,” Sayler said. “We studied the basic biochemistry of this enzyme and learned more about its mechanism of infection.”
The fungus enters the rice plant using a specific kind of polysaccharide monooxygenase, or PMO, that penetrates the rice plant’s leaves.
According to Sayler, the research team is interested in further studying this mechanism of infection in the future.
“This gives us a target to go after to develop new fungicides for a fungus that uses a particular mode of action like this one,” Sayler said. “It allows for a little more specificity in targeting fungi.”
Marletta said that the researchers have found related PMOs in fungi that kill tomatoes, grapes and lettuce. Their goal is to better understand similar entry mechanisms and discover drug molecules that will stop these invasion processes.
Matteo Garbelotto, campus professor in environmental science, policy and management, or ESPM, emphasized the importance of better understanding the disease process in plants.
“In California, there are a whole series of pathogens that affect crops that are relatively well-known,” Garbelotto said. “If you understand a weak link in the disease process, then you have identified an opportunity to stop the disease cycle.”
According to Garbelotto, the research done by Marletta and his team is especially important since rice is one of the biggest staple crops in the world. He also noted that there are certain fungi that can be helpful in agriculture, including some which are “absolutely essential” for crop growth, such as mycorrhizal fungi.
Garbelotto previously studied the use of fungi to prevent the growth of invasive trees in French Polynesia, and he discovered that a certain type of fungus found in plants, called endophytes, actually protected the plants from disease.
“Because of the extended drought in many parts of the world, rice is going through tough times right now,” Garbelotto said. “It’s possible that some of these endophytic fungi could make it possible to keep growing rice even as conditions become tougher.”