University of Purdue Sequencing Genes for Dangerous Fungus

At Purdue University, Jin-Rong Xu, a Purdue University molecular biologist, is searching for the genes involved in the infection process relevant to the fungus Fusarium graminearum, which spawns the worst cereal grains disease known and can also produce toxins potentially fatal to livestock and people.

Wheat and barley in particular are destroyed by the graminearum fungus. Infection in U. S. crops over the last ten years has resulted in an estimated $10 billion in damages. Scientists have sequenced the fungus' genes and are studying the mapped genetic make-up in the hope that it 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.

Sequencing occurs after researchers located all the genes on the fungus' chromosomes and then determine the genes' chemical make-up.

"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."

"Because we now have the genome sequence and a microarray containing the whole genome, it will help us determine what genes allow this fungus to behave as it does," Xu said. "It also will make it easier to identify and determine the function of similar genes in other pathogens and their plant interactions."

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 Fusarium graminearum fungus exists worldwide. It cuts crop yield and damages grain quality. In addition it produces mycotoxins that can be dangerous or even fatal.