Contrasting Roles of Deoxynivalenol and Nivalenol in Host-Mediated Interactions between Fusarium graminearum and Sitobion avenae.

Jassy Drakulic,Olubukola Ajigboye,Toby Bruce,Mohd Haziq Kahar,Rumiana V Ray

doi:10.3390/toxins8120353

Jassy Drakulic, Olubukola Ajigboye + Show 3 more

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https://doi.org/10.3390/toxins8120353

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Journal: Toxins	Publication Date: Nov 30, 2016
Citations: 12	License type: CC BY 4.0

Affiliation: University of Nottingham, Rothamsted Research

Abstract

Fusarium graminearum is the predominant causal species of Fusarium head blight in Europe and North America. Different chemotypes of the species exist, each producing a plethora of mycotoxins. Isolates of differing chemotypes produce nivalenol (NIV) and deoxynivalenol (DON), which differ in toxicity to mammals and plants. However, the effect of each mycotoxin on volatile emissions of plant hosts is not known. Host volatiles are interpreted by insect herbivores such as Sitobion avenae, the English grain aphid, during host selection. Previous work has shown that grain aphids are repelled by wheat infected with DON-producing F. graminearum, and this study seeks to determine the influence of pathogen mycotoxins to host volatile chemistry. Volatile collections from infected hosts and olfactometer bioassays with alate aphids were performed. Infections with isolates that produced DON and NIV were compared, as well as a trichothecene deficient transformant derived from the NIV-producing isolate. This work confirmed the repellent nature of infected hosts with DON accumulation. NIV accumulation produced volatiles that were attractive to aphids. Attraction did not occur when NIV was absent and was, therefore, a direct consequence of NIV production.

Highlights

Fusarium head blight (FHB) is a fungal disease caused by a complex of pathogens from the genusFusarium, and F. graminearum is the most prevalent species in North America [1] and Europe [2,3] at present
Trichothecene mycotoxins produced by Fusarium species are a group of toxic chemicals formed from tetracyclic sesquiterpenoids with an epoxy-ring at the C12,13 position and can be classed into Type A or B depending on the absence or presence, respectively, of a ketone functional group at the C8 position and a hydroxyl group at C7
The prevalence of different F. graminearum chemotypes varies according to geographical region, with NIV chemotypes prevailing in Asia and DON chemotypes prevailing in Europe and North

Summary

Introduction

Fusarium head blight (FHB) is a fungal disease caused by a complex of pathogens from the genus. F. graminearum is the most prevalent species in North America [1] and Europe [2,3] at present. Trichothecene mycotoxins produced by Fusarium species are a group of toxic chemicals formed from tetracyclic sesquiterpenoids with an epoxy-ring at the C12,13 position and can be classed into Type A or B depending on the absence or presence, respectively, of a ketone functional group at the C8 position and a hydroxyl group at C7. The prevalence of different F. graminearum chemotypes varies according to geographical region, with NIV chemotypes prevailing in Asia and DON chemotypes prevailing in Europe and North A legal limit for DON has been set in Europe for different categories of grain products, with a maximum of 1250 μg·kg−1 DON in wheat grain intended for human consumption [6].

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