Research on endophytes in Yellowstone National Park has the potential to impact future agriculture in Oklahoma and around the world.

The research was performed by Marilyn Roossinck, Ph.D., a professor with The Samuel Roberts Noble Foundation, and could yield important information for naturally improving environmental tolerances in plants.

Roossinck's paper detailing her four-year study will be included in the January edition of Science, a weekly, peer-reviewed journal that publishes original scientific research. Entitled A virus in a fungus in a plant: three-way mutualistic symbiosis required for thermal tolerance, Roossinck wrote the paper with her co-authors Luis Márquez, Regina Redman and Rusty Rodriguez.

The paper describes Roossinck's successful efforts to better understand the mutually beneficial relationship between plants and endophytes - a naturally occurring fungus that imparts beneficial characteristics to the hosting plant, including improved tolerances to environmental conditions.

The interaction between plants and fungal endophytes is not fully understood, but Roossinck's findings show that an unlikely entity - a virus - within the endophytes at Yellowstone play an important role in this relationship.

Roossinck believes the practical application of the research could be substantial. Research on how viruses and endophytes assist plants in environmentally difficult circumstances could yield new crops having valuable, naturally induced traits, including enhanced heat, drought or salt tolerances.

"With global warming and depleted soil conditions, agricultural crops are going to have to survive in more extreme environments, and knowing how plants naturally survive in these environments will be important to the future of agriculture," Roossinck said.

Roossinck's research on fungal viruses actually began where we are today - with an article in Science. In 2002, Roossinck read a fascinating story about panic grass, which grows in the geothermal soils in Yellowstone National Park. The article detailed how fungal endophytes within the grass were enabling it to survive in soil with temperatures too high for most plants.

"I wanted to study persistent viruses, which are viruses that can stay with host plants for generations," Roossinck said. "Since fungal viruses are often persistent, I wondered if fungal viruses were involved with the plant-endophyte interactions and to what extent."

She contacted Redman, Rodriguez and Joan Henson, who had performed the original panic grass study, and asked to examine endophytes isolated from harvested plant material. Soon she was analyzing countless samples from their work. Roossinck found what she was looking for - evidence of a virus within the endophytes.

To see if the virus contributed to the plant-endophyte relationship, Roossinck had to "cure" the endophyte of the virus and examine whether the plant changed because of the virus' absence. Collectively, the research team attempted a variety of experiments to remove the virus, but nothing worked.

"It was serendipitous," said Roossinck, smiling as she recalled when they finally discovered how to cure the endophytes. "I was freezing a sample to do another experiment. When we unthawed the sample and began work, we realized the virus was gone."

She began comparing plants having endophytes that included a virus with plants having virus-free endophytes. Roossinck discovered that without both the endophyte and the virus, the plant could not tolerate elevated soil temperatures such as those found in Yellowstone.

"I hope people think differently about viruses," Roossinck said. "Most people think of disease when they think of viruses, but this research clearly demonstrates how they can be beneficial. The plant, the endophyte and the virus have formed a mutualistic relationship that benefits all three entities."

According to the publication's Web site, Science accepts less than 10 percent of its annual submissions. A board of reviewing editors, which comprises 120 scientists worldwide and 20 staff editors with Ph.D. and postdoctoral training scrutinize each manuscript for inclusion. About 75 percent of all submitted articles are rejected during the initial screening.

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Photo:

Marilyn Roossinck

News Release Issued: January 29, 2007

The Samuel Roberts Noble Foundation, Inc. (www.noble.org), headquartered in Ardmore, Okla., is a nonprofit organization conducting agricultural, forage improvement and plant biology research; assisting farmers and ranchers through educational and consultative agricultural programs; and providing grants to nonprofit charitable, educational and health organizations.