Reduced virulence of trichothecene antibiotic-nonproducing mutants of Gibberella zeae in wheat field tests

作者：Anne E. Desjardins, Robert H. Proctor, Susan P. McCormick, Thomas M. Hohn · 年份：1997 · 被引用次数：21 · 研究领域：Mycotoxins in Agriculture and Food、Plant Disease Resistance and Genetics、Plant Pathogens and Fungal Diseases

The role of trichothecene antibiotics in the virulence of the fungus Gibberella zeae (anamorph Fusarium graminearum) on wheat (Triticum aestivum) has been analyzed. Trichothecene-nonproducing mutants of G. zeae were obtained by disrupting Tri5, the gene encoding trichodiene synthase, which catalyzes the first committed step in the trichothecene biosynthetic pathway. Virulence was assessed under field conditions in 1994 and 1995 by controlled inoculation of G. zeae spore suspensions into flowering wheat heads. Trichothecene- nonproducing (Tri5-) mutants were less virulent than trichothecene-producing (Tri5+) parental and revertant strains in their ability to cause head scab on field-grown wheat. Although trichothecene-nonproducing strains colonized wheat heads, the infected heads showed less disease by several parameters tested, including head blenching symptoms, seed weight, seed viability, and trichothecene contamination. This evidence indicates that trichothecene antibiotics are virulence factors in wheat head scab.