When someone says, “DNA,” we think of human genetics and how baby Joe has great-grandpa Harry's nose or ears. Or, maybe we think of crime scenes. (Thank you, “CSI.”). What we probably aren't thinking about is soybean DNA. Thankfully, there are many researchers who are, and over the past two to three years they've been able to sequence the soybean genome.
“The DNA sequencing of the soybean genome itself began about three years ago, when the U.S. Department of Energy announced it was going to fund the project,” says Jim Specht, professor of soybean genomics at University of Nebraska-Lincoln. “The soybean genome sequence represents the genetic code for all things soybean, so to speak.
“We now have knowledge of most, if not all, soybean genes,” he says. “This knowledge is crucial for scientists to begin understanding how the genomic sequences govern soybean plant metabolism, physiology and eventually the agronomic traits of interest to producers.”
Rick Stern, who farms 1,500 acres near Cream Ridge, NJ, is looking forward to the value the soybean genome sequence will bring to farmers.
“The No. 1 value for farmers is that new and better varieties will be available faster than before,” he says. “In the past it's taken a breeder five to 10 years to find a trait of interest, like high yield, then another five to 10 years to get it bred into beans for the field. Now breeders can look at the genome, find the trait on the marker and have it to the farmer in three to five years.”
It's those molecular markers that are having the biggest impact on improving the efficiency of soybean breeding, according to Gary Stacey, professor of plant sciences, University of Missouri. “The big boon in the breeding field is molecular markers. We have the entire genome of soybean, and now we can generate hundreds of thousands of markers very rapidly,” he says. “It's greatly speeding up the ability to develop elite cultivars.”
THE SOYBEAN GENOME sequence, published on Jan. 14 in the Nature journal, is already proving to be a great resource for trait improvements in the science world.
“We're currently using markers to discover regions in the genome that govern seed protein and oil content,” says Specht. “We have found some new chromosome regions that heretofore were not known to have an impact on soybean seed protein and oil. We'll be taking a close look at the genomic sequence in these regions to determine their genes.”
The genome sequence provides researchers, both public and private, with a parts list, says Stacey. “There's still a lot to be done to understand how those parts go together to control the important agronomic traits of the soybean,” he says. “But, completing the sequence is a major accomplishment. What's really exciting, though, is what it's going to allow us to do in the future.” Access to the sequence will allow for more research.
“Several years ago the United Soybean Board (USB) had a project that released all the lines in the USDA library to any public or private breeder who could use them. When that was made public, it made lines from private companies available because it was no longer a secret about who had what,” says Stern, who serves on the USB production committee. “Having the soybean genome sequence in the public domain will make it a very even playing field, and hopefully bring about a little friendly competition, which will be better for farmers.”
The corn genome sequence is complete, as well, and was published in the journal Science in November 2009.
According to the National Science Foundation (NSF), the new genome sequence promises to advance the basic research of maize and other grains, and it will help scientists and breeders improve maize crops.
“Production of a high-quality maize genome sequence was a high priority for the National Plant Genome Initiative form the beginning,” says Jane Silver-thorne of NSF. “This accomplishment builds on technological advances and basic research into maize biology that were essential to the design of the most cost-effective strategy to assemble and anchor the genes onto genetic and physical maps.”
The newly published corn genome sequence has significant refinements over the draft sequence released in February 2008. They include elimination of redundancy and improvements in the ordering and orientation of chromosomal segments, says NSF.