Invited Presenter

Christopher Toomajian ¹
1. Kansas State University, Department of Plant Pathology, Manhattan, Kansas
Corresponding Author: Christopher Toomajian, toomajia@ksu.edu

Toomajian, Christopher

toomajia@ksu.edu

For the past USWBSI funding cycle, PBG has had two majors goals: characterize plant-fungal interactions to identify important genes, proteins, or small molecules that may be used to develop FHB resistance or reduce DON contamination in barley and wheat; and discover epiphytic and endophytic microbes and microbial communities useful for development of FHB control. The following significant accomplishments have been made: 1) discovered that aggressiveness does not segregate with the 3ADON/15ADON chemotypes in progeny from a genetic cross; 2) identified single nucleotide polymorphisms (SNPs) associated with fungal growth, fungicide resistance, and toxin production using genome-wide association studies; 3) identified multiple Fusarium species and chemotypes in surveys of symptomatic wheat and barley, including nivalenol (NIV) strains present in the collection from Illinois; 4) developed and tested a new method for identifying and quantifying FHB-causing species in grain samples; 5) determined that barley resistance varied by the strains used for inoculations; 6) characterized G protein-coupled receptors (GPCRs) critical for F. graminearum pathogenesis, and characterized the regulatory roles of TRI6 and TRI10 in DON production. To utilize the critical fungal pathogenesis genes to reduce FHB and mycotoxin contamination, two RNAi delivery systems, spherical nucleic acid nanomaterials and fungal endophyte-mediated RNAi silence, were developed. Although both RNAi delivery systems appeared to work, they did not lead to a practical application. Since we have gained abundant knowledge in Fusarium genomics, transcriptomics, secondary metabolites, and pathogenesis, the future needs and challenges are to translate this knowledge to address FHB and mycotoxin contamination in wheat and barley.

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