A team of scientists led by Washington University has begun to unlock the genetic secrets of corn, a crop vital to U.S. agriculture. The researchers have completed a working draft of the corn genome, an accomplishment that should accelerate efforts to develop better crop varieties to meet society’s growing demands for food, livestock feed and fuel.
Corn, also known as maize, underlies a myriad of products, including food, household products and ethanol.
The genetic blueprint was announced Feb. 28 by the project’s leader, Richard K. Wilson, Ph.D., director of WUSTL’s Genome Sequencing Center, at the 50th Annual Maize Genetics Conference in Washington, D.C.
“This first draft of the genome sequence is exciting because it’s the first comprehensive glimpse at the blueprint for the corn plant,” Wilson said. “Scientists now will be able to accurately and efficiently probe the corn genome to find ways to improve breeding and subsequently increase crop yields and resistance to drought and disease.”
The $29.5 million project was initiated in 2005 and is funded by the National Science Foundation and the U.S. Departments of Agriculture and Energy.
The team working on the endeavor, including scientists at the University of Arizona in Tucson, Cold Spring Harbor Laboratory in New York and Iowa State University, has already made the sequencing information accessible to scientists worldwide using an online database. The data is also available at maizesequence.org.
The draft covers about 95 percent of the corn genome, and scientists will spend the remaining year of the grant refining and finalizing the sequence.
The group sequenced a variety of corn known as B73 developed at Iowa State decades ago. It is noted for its high grain yields and has been used extensively in both commercial corn breeding and in research laboratories.
The genome will be a key tool for researchers working to improve varieties of corn and other cereal crops, including rice, wheat and barley.
“There’s a lot of great research on the horizon,” said plant biologist Ralph S. Quatrano, Ph.D., the Spencer T. Olin Professor and chair of the Department of Biology in Arts & Sciences. “The genome will help unravel the basic biology of corn. That information can be used to look for genes that make corn more nutritious or more efficient for ethanol production, for example.”
Corn is only the second crop after rice to have its genome sequenced, and scientists will now be able to look for genetic similarities and differences between the crops, Quatrano said.
The genetic code of corn consists of 2 billion bases of DNA, the chemical units that are represented by the letters T, C, G and A, making it similar in size to the human genome, which is 2.9 billion letters long. By comparison, the rice genome is far smaller, containing about 430 million bases.
“Sequencing the corn genome was like putting together a 1,000- piece jigsaw puzzle with lots of blue sky and blue water, with only a few small sailboats on the horizon,” Wilson said. “There were not a lot of landmarks to help us fit the pieces of the genome together.”
The United States is the world’s top corn grower, producing 44 percent of the global crop. In 2007, U.S. farmers produced a record 13.1 billion bushels of corn, an increase of nearly 25 percent over the previous year, according to the U.S. Department of Agriculture.