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Impact of new emerging Fusarium strains on mycotoxins in Ontario

Principal Investigator: Art Schaafsma and Jennifer Geddes-McAlister

Research Institution: University of Guelph

Timeline: June 2023 – July 2026  

Objectives: [PB1] 

  • Using OMAFRA wheat and corn survey determine the annual distribution of these new strains to see if they are taking over.
  • Determine whether NX strains of Fusarium are more virulent and toxigenic than the original 15 ADON strains.
  • If the second objective is true, then determine why by measuring the changes in plant protein production profiles between 15 ADON-infected vs. NX-infected samples.
  • If the second objective is true, test our defense strategies like resistance and fungicides against these new strains to determine if they are effective enough.
  • To support work by other researchers working in this area (i.e., surveys by A. Tenuta, agronomy, forecasting work, and hybrid testing by D. Hooker and micro biome work for Fusarium by M. Raizada).
  • To train scientist to do LCmsms analyses to support mycotoxin research at Ridgetown and develop an independent research program to keep ahead of emerging mycotoxin issues for GFO.

Impacts: [PB2] 

  • If NX strains come to dominate on Ontario farms and they result in 3-4 times more DON, the grain industry will be faced with more frequent and severe cases of contaminated grain.
  • If fungicides and plant resistance reduce DON for NX strains by the same proportions as they do for 15 ADON strains, then what was an adequate control for 15ADON strains, will not be adequate for NX strains
  • Breeders may have to shift strains that they use to challenge their breeding lines and they may have to seek different sources and mechanism of resistance to combat these new strains. 

Scientific Summary: [PB3] 

Fusarium graminearum is a fungus that causes disease in corn, wheat, barley, and oat. Not only do these diseases affect yield, but the fungus produces toxins that helps it gain access to the plant.  These mycotoxins are harmful to humans and livestock and are regulated in the grain trade.  Left unchecked, contaminated grain and yield losses can cost producers and the grain trade millions of dollars in epidemic years. Originally in Ontario we had one strain of F. graminearum that produced the mycotoxin deoxynivalenol (DON) using 15-A-deoxynivalenol as a precursor molecule.  We called these 15 ADON strains.  Recently by routine surveying we have noticed that a new strain producing a new toxin called 3ANX along with 15 ADON is showing up in the field.  Preliminary experiments have shown that these NX strains result in 3-4 times the amount of  DON in grain in diseased plants, compared with the 15 ADON strains. As these NX strains become more common in Ontario, we worry that DON contamination will become more intense than it is today. 

Partnering with MITACS, we will hire a post doctoral fellow to conduct this research.  To understand the extent and progress of the shift in strains we plan to piggy back on Albert Tenuta’s annual DON survey in wheat and corn and isolate and characterize the F. graminearum strains coming from these samples.  To confirm that the NX strains are resulting in higher DON concentrations, we have selected ten 15 ADON strains that have been collected historically in Ontario, and ten NX strains that were collected within the last three years.  We will make individual inoculations of wheat heads and corn ears and compare the mycotoxin profiles coming from the diseased grain.  We will do some preliminary molecular work to begin to understand the reasons why more DON is produced in grain infected with the NX strains.

The two main tools of defence employed against Fusarium and DON are the use of plant resistance and fungicides.  We will set up inoculated experiments starting in 2023 where these tools are tested against the NX strains compared to the 15 ADON strains to determine whether the current tools are as effective against the new strains.

One important additional benefit of this research is to provide continuity for the Ridgetown Fusarium lab which provides analytical support to other important mycotoxin research and surveillance projects.    

External Funding Partners:

This work was supported by Mitacs through Mitacs Business Strategy Internship.

 [PB1]Dear PI – Please review the objectives listed here to ensure they remain current / accurate. I have pulled them from Part 4- B of your GFO proposal. Thanks.

 [PB2]Dear PI – Please review the impacts listed here to also ensure they remain current / accurate. I’ve pulled them from Part 4 – C of your GFO proposal. Thanks.

 [PB3]Dear PI – I’ve lifted part of the text from your project summary in Part 4 – A of your GFO proposal. Again, please review to ensure that what I’ve listed remains an accurate reflection of your project. Thanks.