Like any researcher, West Virginia University’s Vagner Benedito is thrilled to have co-authored a paper published in the prestigious journal Nature. “It feels good,” he notes. “It’s a dream of many scientists.”

But, like any scientist, he knows that the questions answered by that research are just the foundation for bigger, more complex questions on the horizon.

The article, describing the aspects of a legume plant’s genome sequence that support a symbiotic relationship with a beneficial bacteria, was published in the Nov. 16 edition of the internationally recognized journal.

“This is a tremendous achievement for Dr. Benedito and for WVU,” says Provost Michele Wheatly. “Seeing research of this caliber recognized by publication at this level affirms the university’s commitment to excellence in the STEM fields.”

The article also illustrates the collaborative nature of much contemporary science, technology, engineering and mathematics research. It represents eight years of work by 128 scientists at 31 institutions in eight countries.

“That’s how science works,” says Benedito, an assistant professor of genetics and developmental biology at WVU. “It needs people from every part of the world, contributing their expertise and insight.”

Among food crops, legumes like soybeans and peanuts are unique in their ability to absorb nitrogen from the air and to retain it. Plants need nitrogen, but other major food crops like cereals need to be fed nitrogen in the form of commercially produced fertilizers.

“Nitrogen is the most important nutrient in agricultural systems, but it’s also the most limiting, and it’s the most expensive,” Benedito says.

Production of these fertilizers is an energy-intensive process. Soils aren’t great at holding nitrogen fertilizers, which can lead to chemical imbalances in nearby bodies of water.

“There is a dream in plant science of making cereals like corn and wheat able to fix nitrogen,” Benedito says. “If we can make them do that, then food security is guaranteed.”

Producers would be spared the expense of costly fertilizers. Energy consumption for agriculture would be significantly reduced. Water quality would be improved by the decrease in fertilizer runoff from agricultural concerns.

The research represented in Nature is a small step in that direction.

The international team of scientists determined the genome sequence of a type of legume, Medicago truncatula, a close relative of alfalfa that provides good fodder for genetic research. In mapping the genome sequence, the scholars identified codes for almost 50,000 individual genes.

From there, they sought out genes common to multiple legume species that relate to the plant’s symbiotic relationship with rhizobial bacteria. The bacteria establish themselves in the root cells of the legume plant, allowing the guest to fix nitrogen, while the legume host provides nutrients in return.

Benedito and his collaborators examined the genes related to that symbiosis.

“It’s a milestone in legume biology,” Benedito says. “This will generate further understanding of symbiosis and nitrogen fixation, how legumes develop and make seeds, and how they make compounds not found in other plants.”

The primary work on the genome sequencing was conducted at institutions around the world: the University of Minnesota at St. Paul, the University of Oklahoma at Norman, the J. Craig Venter Institute in Rockville, Md., Genoscope in France and the Wellcome Trust Sanger Institute in England. Other lead institutions included CNRS/INRA in Toulouse, France, the John Innes Centre in the United Kingdom, Samuel Roberts Noble Foundation in Oklahoma, the University of Wageningen in the Netherlands, MIPS in Munich, Germany, Ghent University in Belgium, and the National Center for Genome Resources in Santa Fe, N.M. Benedito was honored to be part of a core group of around 10 principal authors of the paper in Nature.

The research could translate into breeding programs to improve crop protection and quality, among other aspects.

For Benedito’s part, he will be focusing on how legumes and bacteria exchange nutrients through membranes. Specific proteins in the membranes carry out the symbiotic relationship, bringing nitrogen to the legumes and providing the bacteria with nutrients it needs. He is also interested in understanding the genetic factors that influence the development of nodules on legume roots that facilitate the bacterial symbiosis.

He’s aided in his research by two Ph.D. students in the genetics and developmental biology program of WVU’s Davis College of Agriculture, Natural Resources and Design, Lina Yang and Christina Wyman.

Yang, who came to WVU from Jiangsu Province, China, has been working with Benedito for a year and a half. She’s studying the functions of a specific gene related to the root nodule’s role in fixing nitrogen. Wyman is interested in understanding how boron is related to nitrogen fixation and which transporter is responsible for delivering borate to nitrogen-fixing nodules.

Benedito’s lab has established a partnership with Michael Udvardi, a professor with the Samuel Roberts Noble Foundation in Ardmore, Oklahoma. The Noble Foundation is an independent, non-profit institute that conducts plant science research and agricultural programs to enhance agricultural productivity regionally, nationally and internationally. Benedito worked for the Noble Foundation prior to joining the faculty in WVU’s Davis College.



CONTACT: David Welsh, Davis College of Agriculture, Natural Resources and Design

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