December 9, 2008

The release this week of the complete draft assembly of soybean's genetic code is a "stupendous achievement" that will lead to further advances in breeding strategies for one of the world's most valuable crops, said a UNL scientist who's been involved in research leading to the breakthrough.

The U.S. Department of Energy's Joint Genome Institute announced the development Monday.

Soybean not only accounts for 70% of the world's edible protein, but also is an emerging feedstock for biodiesel production. Soybean is second only to corn as an agricultural commodity and is the leading U.S. agricultural export.

Jim Specht, UNL soybean geneticist, was part of the research team that created the first comprehensive genetic map for all 20 soybean chromosomes nearly a decade ago.

Specht compared his team's work to creating mileposts on a cross-country highway. Subsequent research has filled in the road between those mileposts.

Research indicates soybeans have as many as 66,000 genes — about half the number identified in the human genome sequence, Specht said.

"It's incredibly complex," he added.

The development has far-reaching ramifications, the U.S. Department of Agriculture's leading scientist said.

"Soybeans have been an important food plant providing essential protein to people for hundreds of years," said Gale Buchanan, USDA's chief scientist and undersecretary for research, education and economics, in a news release from DOE. "Now, with the new knowledge available through this joint DOE/USDA genome sequencing project, researchers everywhere will be able to further enhance important traits that make the soybean such a valuable plant. It's a great day for agriculture and people everywhere."

Specht agreed.

"It's a stupendous achievement," he said. "I never thought I'd see it in my lifetime."

"Soybean is one of the largest and most complex plant genomes sequenced by the whole genome shotgun strategy," said Dan Rokhsar of DOE's Joint Genome Institute. The process entails shearing the DNA into small fragments enabling the order of the nucleotides to be read and interpreted.

The DOE's interest in sequencing the soybean centers on its use for biodiesel, a renewable, alternative fuel with the highest energy content of any alternative fuel. According to 2007 U.S. Census data, soybean is estimated to be responsible for more than 80% of biodiesel production.

Specht noted that this nitrogen-fixing legume crop offers the dual benefit of a seed high in protein and oil — with room for improvement.

"With the advent of low-cost re-sequencing technologies, soybean scientists now have the means to identify sequence differences responsible for yield potential — the most desired of all crop traits, but to date, the most intractable to manipulate by mechanistic methods," Specht said.

The soybean genome project is already making its mark in the field, the DOE said.

"It's tremendous that the soybean genome is out in the public's hands," said Rick Stern, a New Jersey soybean farmer and chair of the production research program for the United Soybean Board. "Now every breeder can go into this valuable library for the information that will help speed up the breeding process. It should cut traditional breeding time by half from the typical 15 years."

Dan Moser
IANR News Service