Plant organ cultures as masked mycotoxin biofactories: Deciphering the fate of zearalenone in micropropagated durum wheat roots and leaves.

Laura Righetti,Enrico Rolli,Chiara Dall’Asta,Renato Bruni,Michele Suman,Gianni Galaverna,Sabrina Sarrocco

doi:10.1371/journal.pone.0187247

Laura Righetti, Enrico Rolli + Show 5 more

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https://doi.org/10.1371/journal.pone.0187247

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Abstract

“Masked mycotoxins” senso strictu are conjugates of mycotoxins resulting from metabolic pathways activated by the interplay between pathogenic fungi and infected plants. Zearalenone, an estrogenic mycotoxin produced by Fusarium spp, was the first masked mycotoxin ever described in the literature, but its biotransformation has been studied to a lesser extent if compared to other compounds such as deoxynivalenol. We presented herein the first application of organ and tissue culture techniques to study the metabolic fate of zearalenone in durum wheat, using an untargeted HR-LCMS approach. A complete, quick absorption of zearalenone by uninfected plant organs was noticed, and its biotransformation into a large spectrum of phase I and phase II metabolites has been depicted. Therefore, wheat organ tissue cultures can be effectively used as a biocatalytic tool for the production of masked mycotoxins, as well as a replicable model for the investigation of the interplay between mycotoxins and wheat physiology.

Highlights

Modified mycotoxins have recently become a prominent issue in food safety research and risk assessment, due to the increasing awareness of possible toxic effects related to theiroccurrence in food
Two separate amounts were administered after previous checking the tolerance of cultured leaves and roots during the whole time course of the experiment, in order to avoid concentrations known for causing toxicity in maize root cells and barley seedlings [38]
The final ZEN concentrations in the growing medium were 12.5 and 100 μg/L, respectively. In both Kofa and Svevo cultivars the mycotoxin was quantitatively absorbed after 7 days in leaves, with minor differences between the two administered amounts (Fig 2)

Summary

Introduction

Modified mycotoxins have recently become a prominent issue in food safety research and risk assessment, due to the increasing awareness of possible toxic effects related to their (co)occurrence in food. Several masked mycotoxins have been described in cereals so far, including derivatives of deoxynivalenol (DON), nivalenol, T-2 and HT-2, alternariol and alternariol methyl ether [1, 2]. Being lipophilic, these compounds may cross the membrane and distribute into plant cell organelles, where they both exert their toxicity and are exposed to enzymatic pools.

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