Study a step toward disease-resistant crops, sust...( WEST LAFAYETTE Ind. - A five-year st...)

WEST LAFAYETTE, Ind. - A five-year study that could help increase disease resistance, stress tolerance and plant yields is under way at Purdue University.

The $4 million project uses a new technique called "mutant-assisted gene identification and characterization," or MAGIC, to identify potentially useful gene combinations in crop species.

"If we can understand these genes better, we could engineer plants to be immune to most diseases," said principal investigator Guri Johal, an associate professor of botany and plant pathology.

First using the corn genome, the method will add to the collection of useful alleles, or pairs of genes, that create certain traits. This will improve crop gene diversity, a quality that dwindles as crops are bred. Since natural selection has preserved such alleles, they likely confer a selective advantage that increases the ability of plants to survive, Johal said.

The MAGIC technique is described in a review article published this month in the journal Crop Science.

Maize contains more genetic diversity than any other model organism, making it an ideal plant for gene exploration, Johal said. In fact, two lines of corn are more different from one another than humans are from chimpanzees, said study co-author Cliff Weil, a professor of agronomy.

"Maize grows in places as different as northern Quebec, where it is cold and growing seasons are short, and the Mexican highlands, where it is very hot and dry," he said. "Natural adaptation to different environments has come by combining just the right sets of alleles in each variation."

MAGIC is a new tool needed to find genes, Johal said. Many recent research methods used to this end involve mutagenesis, with scientists deliberately causing a specific gene or genes to malfunction in order to determine the gene's impact on the plant.

"Mutagenesis has worked well, but we are reaching a period of diminishing returns,"
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