College of Liberal Arts and Sciences at Iowa State University

Coming together

Researchers in LAS and the College of Agriculture have brought their individual projects together to make an important discovery
Once upon a time in the land of plant researchers, three distinctive groups were looking for the identity of the compound that plants use to create oil.

"The groups all started independently," said David Oliver, professor and chair of the botany department. "When we found out that we were working on basically the same project, we decided to pool our resources to figure out how and where this compound was made."

Each group had a different spin on the overall research, but in the end the groups wound up focusing on one chemical. While other plant scientists have searched for 30 years to find the source of the compound that plants use to create oil, the three research groups at Iowa State have made that discovery.

"No one had really determined where the compound came from," Oliver said. "No one knew which route is used in plants."

That all changed with the discovery made by research groups led by Oliver, Basil Nikolau, professor of biochemistry and interim director of the Center for Designer Crops; and Eve Syrkin Wurtele, professor of botany. The results of their research were published in the June issue of the journal, Plant Physiology.

The discovery could make it possible for plant breeders and genetic engineers to adjust the oil-producing capacity of soybeans, corn and other plants.

The three research groups came together after new sequence data became available from the Arabidopsis (mustard) plant genome project. Their research groups worked independently, studying different parts of the same puzzle - trying to find genes that could make acetyl-coenzyme A (acetyl-CoA).

Commercial oils produced by plants are made from fatty acids. The precursor for the biosynthesis of fatty acidsis acetyl-CoA. Soybeans and other plants with oil-producing seeds are a significant source for the oil used in edible products (salad dressings, cooking oils, etc.) and industrial products (lubricants, paints, etc.).

The groups' discovery was also aided by earlier research that acetyl-CoA was made either by the enzyme acetyl-CoA synthetase (ACS), ATP-citrate lyase or pyruvate dehydrogenase (PDH).

"We looked at how the ACS and PDH coding genes are expressed during the development of the seeds when oil was being produced in the seeds," Wurtele said. "It turned out that the PDH gene is expressed coordinately with other fatty acid biosynthetic genes consistent with its role in making oil, but the expression of the ACS gene was not coordinated with the other fatty acid biosynthetic genes or oil accumulation."

So what does this mean? Oliver says that if plant breeders can increase the amount of oil derived from soybeans and other plants, the economic impact would be considerable on Iowa agriculture.

" Iowa can grow corn and soybeans better than anyone in the world," he said. "Anything we can do to make corn and soybeans more valuable will be commercially good for this state.

"Vegetable oils are one step away from running cars," he continued. "Right now, there is 10 percent oil in corn. If plant breeders can figure out a way to make it 30 percent, then we may have a viable alternative to run cars and heat homes."

Wurtele agrees with her colleague.

"Hopefully we can control not only the quantity of the oil, but the quality of the oil, so that Iowa agriculture can produce a high-value product," she said.