This fall, thousands of college freshmen across the United States will attend a fundamental class in biology, and Marilyn Roossinck's work will be there to teach them.

A virologist and professor with The Samuel Roberts Noble Foundation, Roossinck, Ph.D., performed a four-year study on a three-way symbiotic relationship between a virus, a fungus and a plant that was published in McGraw Hill's new college textbook, "Biology: Concepts and Investigations." The textbook entered circulation this semester.

"I am passionate about educating people about science and its importance in understanding the world around us," Roossinck said. "It is particularly fulfilling to be included in a textbook that will be seen by countless students for years to come."

The textbook excerpt describes Roossinck's successful efforts to better understand the mutually beneficial relationship between plants and endophytes - naturally occurring fungi that impart beneficial characteristics to host plants, including improved tolerances to environmental conditions.

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 hosts for generations," Roossinck said. "Since fungal viruses are often persistent, I wondered if they were involved with the plant-endophyte interactions and to what extent."

She contacted Drs. Regina Redman, Rusty 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's absence. Collectively, the research team attempted a variety of experiments to remove the virus, but nothing worked.

"It was serendipitous," Roossinck said. "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."

The research performed by Roossinck, along with her collaborators, Drs. Luis Márquez, Redman and Rodriguez, could yield important information for naturally improving environmental tolerances in plants.

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

Roossinck's research story has already been published in "Science," a highly prestigious peer-reviewed journal that publishes original scientific research.

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Photo:

Marilyn Roossinck, Ph.D.

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News Release Issued: October 21, 2008

For media inquiries concerning the Noble Foundation, please contact J. Adam Calaway, Director of Public Relations, at 580.224.6209 or by email at jacalaway@noble.org.

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.