Purdue University scientists led an effort to sequence the soybean genome, giving researchers a better understanding of the plant's genes and how to use them to improve its characteristics.

Agronomy professor Scott Jackson said the U.S. departments of Energy and Agriculture study found that the soybean has about 46,000 genes, but many of those - 70 percent to 80 percent - are duplicates. This duplication may make it difficult to target the genes necessary to improve soybean characteristics such as seed size, oil content or yield.

Adding to the difficulty, Jackson said many of the duplicated genes in the soybean genome have been shuffled, making it hard to predict where the duplicate copies of a gene might be. This complicates the genetics and breeding of soybeans.

"If I'm selecting for a gene, I may have difficulty in locating all the necessary duplicates of that gene," said Jackson, corresponding author on the soybean genome paper that was published Wednesday (Jan. 13) on the cover of the journal Nature. "It has a lot of backup copies."

Despite the difficulties the soybean genome presents, having a sequenced genome does speed up the work scientists are able to do to improve the plant's characteristics. Genome sequencing eliminates the need for meticulous searches for particular genes.

"It really is going to change the way we ask questions about soybeans in research," said Randy Shoemaker, a research geneticist from the U.S. Department of Agriculture's Agricultural Research Service at Iowa State University and the paper's co-author. "What used to take us literally years can take us weeks or months now. This is the entire genetic code in front of you."

www.purdue.edu/newsroom/research/2010/100113JacksonSoybean.html