A high proportion of NX-2 mycotoxin producing strains are found among Fusarium graminearum isolates from northeastern New York State

Authors: LOFGREN, LOTUS - University Of Minnesota; Riddle, Jakob; DONG, YANHONG - University Of Minnesota; KUHNEM, PAULO - Federal University Of Rio Grande Do Sul; CUMMINGS, JAIME - Cornell University; DEL PONTE, EMERSON - Federal University Of Rio Grande Do Sul; BERGSTROM, GARY - Cornell University; Kistler, Harold

Submitted to: European Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2017
Publication Date: 10/24/2017
Citation: Lofgren, L., Riddle, J.M., Dong, Y., Kuhnem, P.R., Cummings, J.A., Del Ponte, E.M., Bergstrom, G.C., Kistler, H.C. 2017. A high proportion of NX-2 mycotoxin producing strains are found among Fusarium graminearum isolates from northeastern New York State. European Journal of Plant Pathology. 150:791-796.
DOI: https://doi.org/10.1007/s10658-017-1314-6

Interpretive Summary: Fusarium graminearum and related fungi are responsible for Fusarium head blight (FHB) and other economically destructive diseases of wheat, barley, and other cereals world-wide. In addition, these fungi contaminate grain with trichothecene mycotoxins that pose a significant threat to food safety and animal health. This leads to enormous losses of food and feed worldwide as well as to high costs for monitoring and mycotoxin management to protect consumers. In this research, we describe strains of F. graminearum from New York State that produce a previously unrecognized trichothecene toxin, termed NX-2. We determined that the frequency of strains producing this toxin are higher than the frequency observed in the Upper Midwestern U.S. by approximately 10 fold. As such, the results reported here are critical to promoting food safety and cereal production through improved understanding of regional fungal diversity that can inform efforts to breed cereals with broad resistance to FHB.

Technical Abstract: Fusarium graminearum, a fungal pathogen of wheat, barley, and corn, produces a variety of trichothecene mycotoxins that are important as aggressiveness factors and as seed contaminants reducing grain quality. A previous survey of the pathogen in New York State identified variation in genes indicative of trichothecene diversity. Recently F. graminearum strains that produce a new trichothecene mycotoxin called NX-2 have been identified from North America. Using a large collection of F. graminearum strains from Willsboro NY, we found that the frequency of NX-2 producing strains was seven - to fourteen times higher than at other locations where it was reported previously. NX-2 producers were not only found on wheat heads but also found in high frequency from air samples and on maize ears, stalks, and stubble. Because strains producing NX-2 may represent as much as 20% of the total F. graminearum population, regional plant breeding efforts should take into account the frequency of this novel trichothecene.