Compiled from media reports

Several dozen researchers, including 10 at the University of Arizona, have reached a milestone in the realm of plant genetics: they have finished a draft genome sequence for corn, or maize, one of the world's most broadly cultivated and multipurpose crops. The project's lead investigators predict that the genetic blueprint they have produced will help scientists improve the yield and hardiness of corn and other principal crops.

Completing the project, launched in 2005 with $29.5 million in funding from the National Science Foundation (NSF), and led by Washington University, Saint Louis, is especially impressive given the size of the maize genome. It has roughly the same number of base pairs as human beings, although its 10 chromosomes contain around 60,000 genes, compared to about 26,000 genes for human beings.

Rod Wing, director of UA's Arizona Genomics Institute and a member of the BIO5 Institute at UA, was one of the project's co-principal investigators, and led the group that produced the physical map of the genome for B73, a variety of maize developed at Iowa State University several decades ago. Dr. Wing's task consisted of arranging 18,000 pieces of genetic material in the proper order, and with the proper orientation.

"Imagine that the genome was divided up into pieces and that these pieces are all scrambled in a box, like a puzzle," Dr. Wing said. "Using various physical and genetic mapping techniques, we put the pieces into the correct order and orientation."

The project, part of the National Plant Genome Initiative, targets for sequencing those plants with the greatest economic importance and potential economic value. Learning more about maize should also lead to new understanding of other cereals, such as rice, which share ancestors with maize. Dr. Wing was a major contributor to the decoding of the rice genome, which was completed in 2005.

"Creating a completed draft of the corn genome brings us one step closer to our goal of understanding the functional genetic components that influence hybrid vigor, drought and pest resistance, and asexual plant reproduction or apomixes—all special traits that make corn valuable," explained James Collins, head of the Biological Sciences Directorate at the NSF, and formerly an Arizona State University professor.

"Corn and rice comprise about 80 percent of the food in the world," Dr. Wing said in the Arizona Daily Star. "By understanding these organisms more precisely, (we should be) able to have a more stable food supply, meet the needs of the future—and maybe the energy demands."

The potential to fulfill those objectives engendered enthusiasm for the project among commercial corn producers, said Vicki Chandler, director of the BIO5 Institute and herself a maize researcher.

"It's huge," Dr. Chandler said in the Daily Star. "This has been on the drawing boards for the National Corn Growers Association and a number of other constituencies across the country since the mid-'90s. Maize is in the U.S. the most economically important crop, and it's a huge source of food, fiber, and animal feed."

The sequence information for maize that the project yielded has been deposited in a free online database called GenBank, and is accessible at maizesequence.org.

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For more information:

"UA scientists crack corn genome," Arizona Daily Star, 03/03/2008

UA media release

National Science Foundation media release