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Nitrogen, Phytochemicals, BIOAg

Posted by | October 22, 2008

Getting the Fix on Nitrogen

Nitrogen is an essential nutrient for plant growth, but not all forms of nitrogen are usable by plants. Although Earth’s atmosphere is rich in nitrogen, the inert atmospheric gas is useless to most organisms.

Some plants, though, form symbiotic relationships with bacteria called rhizobia. In a complicated exchange of nutrients, rhizobia produce an abundance of nitrogen, making it available to the plant. Legumes, such as such as alfalfa, soybeans, chickpeas and lentils, are especially good at fixing nitrogen. Grown as cover crops in order to enrich soil, legumes are typically higher in protein than other crop plants, probably due to their symbiosis with nitrogen-fixing bacteria.

Michael Kahn, professor in WSU’s Institute of Biological Chemistry and the School of Molecular Biosciences, is a member of a team that sequenced the genome of a rhizobia bacterium that infects alfalfa roots. Along with a collaborator at Stanford University, he led an effort to clone and manipulate all 6,200 genes predicted to be in that sequence. To bring down the cost per gene far enough to make it interesting to funding agencies, Kahn’s lab has developed several new genetic-research techniques. Kahn and his team are investigating the function of each gene and how each gene contributes to the bacteria’s ability to persist in the soil, infect alfalfa roots, and lead to a productive, nitrogen-fixing symbiosis.

Investigators hope their research will improve the efficiency of nitrogen fixation, make establishment of the symbiosis more reliable under different growing conditions, and extend the host range of nitrogen-fixing symbiotic relationships. Legumes are often used as a green manure, and the nitrogen they accumulate can be used by subsequent crops grown in rotation. Research into the legume-rhizobia relationship will lead to improved yield, elimination of a major fertilizer input, and improved designs for sustainable agriculture.

For more information on Kahn’s research, please visit:

Top: Michael Kahn; bottom: nitrogen-fixing nodules on a legume root.

Top: Michael Kahn; bottom: nitrogen-fixing nodules on a legume root

An Apple a Day (And a Raspberry, Cherry and Potato, Too)

Research on the benefits of phytochemicals in apples and raspberries will expand to include other major Washington crops, continuing a project that a WSU scientist began last year.

Bernd M. Lange, assistant professor in WSU’s Institute of Biological Chemistry, spearheaded the research project, beginning in the fall of 2007, with the goal of developing a high-throughput analytical method of measuring levels of health-related phytochemicals in crops.

“Phytochemicals, in general, are active chemicals in plants that can be of nutritional value,” Lange said. “There are hundreds of thousands of phytochemicals known; some are toxic to humans, some are beneficial.”

It is the beneficial kind that Lange is investigating and plans to evaluate to see if claims can be made that Washington produce provides health benefits to consumers. In the first year of research, a large number of phytochemicals were identified in apples and raspberries, and correlations were beginning to be made to determine their abundance in particular varieties. This year, Lange said, the focus will be on extending previous work, as well as expanding research to include sweet cherries, potatoes, wheat and milk.

–Bethany Carpenter, Marketing, News, and Educational Communications Intern

For more information on Lange’s research, please visit:

Not only are some phytochemicals health-benefitting, but they're eye candy, too.

Not only are some phytochemicals health-benefitting, but they’re eye candy, too

State of the Organic State, Oct. 28

The State of Organic Agriculture in Washington will be the topic of the keynote presentation at the Washington State University symposium on its biologically intensive and organic agriculture program, or BIOAg.

BIOAg is a comprehensive research and educational program focused on biological processes in farming that are renewable, non-polluting and that provide multiple benefits for farmers and society. Organic farming is one well-developed example of the concept.

John Gardner, WSU Vice President for Extension and Economic Development will speak on the topic “Engaging the University in Sustainability Research, Education and Extension in the 21st Century.” Jessica Goldberger, assistant professor of Community and Rural Sociology, and David Granatstein, WSU sustainable agriculture specialist, will talk about the state of the state’s organic ag sector. Goldberger recently completed the first comprehensive statewide survey of Washington’s organic producers and Granatstein is lead author of WSU’s annual state organic profile.

The symposium will be held on Tuesday, Oct. 28, in the Junior Ballroom of the renovated Compton Union Building on WSU’s Pullman campus. The symposium will begin at 10:10 a.m. with a session of poster presentations by faculty involved in BIOAg research projects. The symposium is open to the public and free of charge.

For more information about the symposium, please visit:

For more information about BIOAg at WSU, please visit:

The BIOAg State of the Organic State, Oct. 28

The BIOAg State of the Organic State, Oct. 28