Scientists unlock clues for tailoring corn plant for food, energy needs

Nov 19, 2009

(PhysOrg.com) -- Scientists have long known that the offspring of two inbred strains tend to be superior to both their parents. Now, a team of researchers including a University of Florida geneticist has discovered clues to why that might be the case for one of the most important crops in the world: corn.

The result could boost scientists' ability to custom-tailor corn for specific traits, such as high content for human consumption or high glucose content for biomass fuel.

"An understanding of the combination of that result in superior performance will influence future breeding programs, which will produce higher yield or improved quality crops to meet the demands of an energy and nutrition hungry world," said Brad Barbazuk, a UF assistant professor in biology and member of the UF Genetics Institute.

The findings are set to appear in the Nov. 20 issues of Science and PLoS Genetics.

With help from the newly released DNA sequence of the common corn strain known as B73, Barbazuk, and colleagues from the University of Minnesota, Iowa State University and Roche NimbleGen, compared the of B73 with that of a second strain, Mo17.

The scientists discovered an astonishing abundance of two kinds of structural variations between the pair: differences in the copy number of multiple copies of certain stretches of , and the presence of large segments of DNA in one but not the other. In fact, at least 180 genes appear in B73 that aren't found in Mo17.

Nathan Springer, an associate professor of at the University of Minnesota's College of Biological Sciences and the lead author of the paper, suspects that Mo17 likely has a similar number of genes that B73 lacks.

"The genomes of two corn strains are much more different than we would have thought," Springer said. "What struck us is how many major changes there are between two individuals of the same species."

The researchers think that this diversity, which is almost as great as the difference between humans and chimpanzees, is what's behind the superiority of hybrids. When the genetic material from the two very different parents combine, the offspring ends up with more expressed traits than either parent - the best of both worlds, gene-wise.

"Hybrid offspring are probably benefiting from obtaining the genes unique to each inbred parent in addition to unique combinations of favorable alleles." Barbazuk said.

In addition, the analysis revealed large regions of low diversity.

"There are large segments that are essentially invariant between the two inbreds," he said. "Some of these sections may have lost diversity as result of selection during the domestication of maize from its ancestor, teosinte, approximately 10,000 years ago."

The findings are important because corn is important.

Domesticated some 10,000 years ago, the crop produces billions of bushels of food, feed, and fuel feedstock each year in the United States alone. If scientists understand the molecular underpinnings of hybrid vigor, Springer said, they can potentially produce true-breeding lines of corn with specific traits for specific uses. That means better use of land, fertilizer, fuel, and other inputs needed to grow , and, ultimately, less environmental impact than might otherwise accrue as we work to meet the needs of a growing population.

Provided by University of Florida (news : web)

Explore further: Team advances genome editing technique

add to favorites email to friend print save as pdf

Related Stories

Researchers begin to solve mystery of hybrid vigor

May 09, 2006

Hybrid vigor works, but no one understands how. ISU plant scientists have uncovered a key to understanding the complex molecular mechanisms of this biological process. Their findings were published in the May ...

Scientists unveil draft sequence of corn genome

Feb 25, 2008

A team of scientists led by Washington University in St. Louis 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 ...

All eyes and ears on the corn genome

Mar 13, 2008

A consortium of researchers led by the Genome Sequencing Center (GSC) at Washington University in St. Louis, Mo., announced today the completion of a draft sequence of the corn genome.

Recommended for you

Team advances genome editing technique

4 hours ago

Customized genome editing – the ability to edit desired DNA sequences to add, delete, activate or suppress specific genes – has major potential for application in medicine, biotechnology, food and agriculture.

Studies steadily advance cellulosic ethanol prospects

Oct 20, 2014

At the Agricultural Research Service's Bioenergy Research Unit in Peoria, Illinois, field work and bench investigations keep ARS scientists on the scientific front lines of converting biomass into cellulosic ...

User comments : 0