Effects of temperature and soil fauna on the reduction and leaching of deoxynivalenol and zearalenone from Fusarium graminearum-infected maize stubbles

Friederike Meyer-Wolfarth,Katherine Muñoz,Stefan Schrader,Elisabeth Oldenburg,Torsten Meiners

doi:10.1007/s12550-021-00434-y

Friederike Meyer-Wolfarth, Katherine Muñoz + Show 3 more

Open Access

https://doi.org/10.1007/s12550-021-00434-y

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Abstract

A microcosm study was conducted at two different temperatures under laboratory conditions to investigate the regulatory capacity and the interactive performance of two soil fauna species (Aporrectodea caliginosa, earthworms, and Proisotoma minuta, collembolans) on the reduction of Fusarium toxins in contaminated maize stubbles. Single and mixed species treatments were exposed to artificially infected maize stubbles highly contaminated with the mycotoxins deoxynivalenol (DON) (10,462 µg kg−1) and zearalenone (ZEN) (2,780 µg kg−1) at 17 °C and 25 °C for time periods of 3 and 6 weeks. Immediately after the respective end of incubation, the microcosms were heavily watered to determine the leaching potential of DON and ZEN from contaminated maize stubbles. Maize residues, soil, and eluted water (percolate) samples were analysed for mycotoxin content using liquid chromatography coupled to mass spectrometry. The biomass of introduced earthworms and number of collembolans were monitored to get information about their adaptability to the experimental conditions. While the decline of ZEN was temperature-dependent, but not influenced by faunal activities, a reduction of DON due to faunal impact was observed by trend. In the leaching experiment, 67–82% of the DON content in the residual maize stubbles leached from the plant material by irrigation and was detected in the soil (1.9–3.4 µg kg−1) and in the percolate (12–295 µg L−1). In the case of ZEN, 27–50% of the mycotoxin leached from the residual maize stubbles due to watering but was only occasionally detected in traces in the soil and not found in the percolate. The results clearly reveal a leaching potential of both DON and ZEN, respectively, but a mobilisation with water was only observed for DON. Temperature confirmed to be a key factor, affecting the fate of the mycotoxins in the soil by driving the interaction between different soil fauna members as well as functional and trophic levels within the soil food web.

Highlights

Current and future agricultural plant production is facing huge challenges due to progressive change of the global climate
Earthworms and collembolans are known to contribute to the biocontrol of plant pathogenic fungi such as Fusarium spp. and are even able to promote the reduction of mycotoxin concentrations in crop residues on the soil surface and in the soil (Meyer-Wolfarth et al 2017a, b; van Capelle et al 2021; Wolfarth et al 2011a, 2013)
The presence of the earthworm and collembolan species in the single faunal treatments did not facilitate a reduction of DON concentration in the maize stubbles observed both after 3 and 6 weeks

Summary

Introduction

Current and future agricultural plant production is facing huge challenges due to progressive change of the global climate. Earthworms and collembolans are known to contribute to the biocontrol of plant pathogenic fungi such as Fusarium spp. and are even able to promote the reduction of mycotoxin concentrations in crop residues on the soil surface and in the soil (Meyer-Wolfarth et al 2017a, b; van Capelle et al 2021; Wolfarth et al 2011a, 2013). The first step should simulate maize stubble degradation left on the soil after harvest during time courses of 3- and 6-week incubation to investigate the regulatory capacity of two soil fauna members and their interactive performance to contribute to the reduction of Fusarium toxins in plant residues. Our hypotheses were as follows: (1) earthworms and/ or collembolans are involved in the reduction of the mycotoxin content of DON and ZEN in contaminated maize material; (2) the interaction between both faunal species results in higher DON and/or ZEN reduction rates in contaminated maize material; (3) temperature affects the faunal mycotoxins reduction efficacy and the contamination levels of DON and ZEN in residual maize material; (4) the mycotoxins DON and ZEN leach from contaminated maize material into the soil and are detected in the percolate (eluted water)

Material and methods

Experimental setup

Results

Discussion