Fungus genome yielding answers to protect grains, people a...( WEST LAFAYETTE Ind. - Why a pathogen...)

WEST LAFAYETTE, Ind. - Why a pathogen is a pathogen may be answered as scientists study the recently mapped genetic makeup of a fungus that spawns the worst cereal grains disease known and also can produce toxins potentially fatal to people and livestock.

The fungus, which is especially destructive to wheat and barley, has resulted in an estimated $10 billion in damage to U.S. crops over the past 10 years. The scientists who sequenced the fungus' genes said that the genome will help them discover what makes this particular pathogen so harmful, what triggers the process that spreads the fungus and why various fungi attack specific plants.

These investigations also may lead to producing plants that are completely resistant to the fungus Fusarium graminearum, something that hasn't been possible previously, said Jin-Rong Xu, a Purdue University molecular biologist. He is pinpointing which genes enable the fungus to cause the disease Fusarium head blight, or scab.

In a recent issue of the journal Science, Xu and an international scientific team reported that certain chromosomal regions in Fusarium graminearum appear to dictate plant and fungus molecular interactions that allow the fungus to contaminate crops and cause disease.

The researchers located all of the genes on the fungus' chromosomes and then determined the genes' chemical makeup, or sequence.

"The Fusarium graminearum genome was easy to assemble because, unlike other fungal genomes, there aren't too many repetitive DNA sequences," Xu said. "It seems that this Fusarium can efficiently detect and remove duplicated sequences or transposable elements, which kept the genome clean and well-organized."

This basic information on the Fusarium graminearum genome will aid in further research and also provide information on other fungi and their interaction with plants, he said.

"Because we now have the genome sequence and a microarray containing the
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