|Kistler, H - Corby|
Submitted to: Molecular Plant-Microbe Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2002
Publication Date: 11/1/2002
Citation: HOU, Z., XUE, C., PENG, Y., KATAN, T., KISTLER, H.C., XU, J. A MAP KINASE GENE (MGV1) IN FUSARIUM GRAMINEARUM IS REQUIRED FOR FEMALE FERTILITY, HETEROKARYON FORMATION, HYPAL GROWTH AND PLANT INFECTION. MOLECULAR PLANT-MICROBE INTERACTIONS. 2002. v. 15. p. 1119-1127. Interpretive Summary: Fungi in the genus Fusarium are arguably the most important group of fungal plant pathogens, causing a variety of blights, root rots, or wilts on nearly every species of economically important plant. Fusarium graminearum, the cause of head blight disease of wheat and barley, has resulted in large economic loss to U.S. agriculture in the last decade. The fungus and the toxic compounds that it produces are hazards to food safety, as ingestion of infested grain is harmful to both humans and livestock. Our goal is to use a genetic approach to understand mechanisms regulating the infection process to wheat and the toxin producing ability in the pathogen. In this paper we describe a gene that is responsible for control of both the process of plant infection and the ability to produce toxins in the plant. Strains we have created that lack the gene produce little disease and have a greatly reduced capacity to produce toxins in the plant. Knowing the manner in which the fungus causes disease and produces toxin may be important in order to develop plants resistant to disease and to develop novel ways to prevent the accumulation of harmful fungal toxins in the food supply. This information will be useful to other scientists who are seeking new ways to develop Fusarium-resistant wheat and barley because it reveals a previously undescribed factor critical to the establishment of head blight disease.
Technical Abstract: Fusarium graminearum is an important pathogen of small grains and maize in many areas of the world. Infected grains are often contaminated with mycotoxins harmful to humans and animals. During the past decade, F. graminearum has caused several severe epidemics of head scab in wheat and barley. In order to understand molecular mechanisms regulating fungal development and pathogenicity in this pathogen, we isolated and characterized a MP kinase gene, MGV1, that is highly homologous to the MPS1 gene in Magnaporthe grisea. The MGV1 gene was dispensable for conidiation in F. graminearum but essential for female fertility during sexual reproduction. Vegetative growth of the mgv1 deletion mutant was normal in liquid media but weak cell walls and were hypersensitive to cell-wall degrading enzymes. Interestingly, mgv1 mutants were self-incompatible when tested for heterokaryon formation and substantially reduced in virulence. Mutants also were greatly reduced in their ability to accumulate trichothecene mycotoxins on inoculated wheat. Our data suggest that MGV1 in F. graminearum if involved in multiple developmental processes related to sexual reproduction, plant infection and cell wall integrity.