title: The Fusarium virguliforme toxin FvTox1 causes foliar sudden death syndrome-like symptoms in soybean.
abstract: Fusarium virguliforme causes sudden death syndrome (SDS) in soybean. The pathogen has never been isolated from diseased foliar tissues; therefore, one or more toxins have been considered to cause foliar SDS development. Cell-free F. virguliforme culture filtrates containing a toxin causes foliar SDS in soybean. A low-molecular-weight protein of approximately 13.5 kDa (FvTox1), purified from F. virguliforme culture filtrates, produces foliar SDS-like symptoms in cut soybean seedlings. Anti-FvTox1 monoclonal antibodies raised against the purified FvTox1 were used in isolating the FvTox1 gene. In the presence of light, recombinant FvTox1 protein expressed in an insect cell line resulted in chlorosis and necrosis in soybean leaf disks that are typical foliar SDS symptoms. SDS-susceptible but not the SDS-resistant soybean lines were sensitive to the baculovirus-expressed toxin. The requirement of light for foliar SDS-like symptom development indicates that FvTox1 induces foliar SDS in soybean, most likely through production of free radicals by interrupting photosynthesis.
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa 50011-1010, USA.
authors.forename: Hargeet K
authors.initials: HK
authors.lastname: Brar
authors.forename: Sivakumar
authors.initials: S
authors.lastname: Swaminathan
authors.forename: Madan K
authors.initials: MK
authors.lastname: Bhattacharyya
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D004271:DNA, Fungal / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000276:immunology / Q000633:toxicity; D005670:Fusarium / Q000235:genetics / Q000472:pathogenicity*; D005800:Genes, Fungal; D054884:Host-Pathogen Interactions / Q000235:genetics / Q000502:physiology; D051379:Mice; D008969:Molecular Sequence Data; D009183:Mycotoxins / Q000235:genetics / Q000276:immunology / Q000633:toxicity*; D010935:Plant Diseases / Q000382:microbiology; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000235:genetics / Q000633:toxicity; D013025:Glycine max / Q000187:drug effects* / Q000382:microbiology*
chemical_list: D000911:Antibodies, Monoclonal; D004271:DNA, Fungal; D005656:Fungal Proteins; D009183:Mycotoxins; D011994:Recombinant Proteins