Uncovering the biofumigant capacity of allyl isothiocyanate from several Brassicaceae crops against Fusarium pathogens in maize

Abstract

BACKGROUND: Driven by environmental concerns, chemical fumigants are no longer allowed in many countries. Therefore, other strategies for reducing fungal inoculum in soils and on crop debris are being explored. In the present study, several Brassicaceae crops were screened for their potential to control Fusarium gramineaum and Fusarium poae mycelial growth in an in vitro inverted Petri dish experiment. Volatile production was measured using gas chromatography-mass spectrometry headspace analysis. A selection of cultivars from each crop species was further investigated using a pot experiment with maize. RESULTS: Ethiopian mustard (Brassica carinata) and brown mustard (Brassica juncea) released volatile allyl isothiocyanate (AITC) and a higher concentration of AITC was correlated with a better fungal growth reduction in the in vitro screening. Brown mustard cultivar Etamine completely inhibited growth of both Fusarium spp. Pure AITC in a solution with methanol resulted in a sigmoid dose-response curve for both Fusarium spp. tested. Fusarium poae appeared to be more tolerant to AITC than F. graminearum. A pot experiment revealed that the incorporation of brown mustard plant material could alleviate the clear negative effect of F. graminearum infection on maize growth. CONCLUSION: The present study demonstrated the correlation between the fungistatic effect of biofumigation crops on Fusarium spp. and their production of volatile AITC in vitro, without the addition of exogenous enzymes, and confirmed the biofumigation potential of brown mustard in a pot experiment with maize. These results may help farmers when selecting a green manure crop suitable for biofumigation.

Effects of Glucosinolate-Derived Isothiocyanates on Fungi: A Comprehensive Review on Direct Effects, Mechanisms, Structure-Activity Relationship Data and Possible Agricultural Applications

“…The most frequently used species are young plants of Brassica juncea , B. napus , B. rapa , B. oleracea , B. carinata and Sinapis alba . The results mainly include disease suppression of the plant of interest in several crop-pathogen pairs [ 48 , 49 , 74 , 75 , 104 , 113 , 152 , 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 , 161 ]. The studies include in vitro, pot and field studies as well, summarized in Table S3 .…”

Full-Season Cover Crops and Their Traits That Promote Agroecosystem Services

“…We found the Brassicaceae significantly reduced the abundance of potential plant fungal pathogens. Brassicaceae, and more specifically mustards, have been deemed ideal for biologically suppressing plant pathogens such as plant parasitic nematodes and fungal pathogens due to their production of glucosinolates and isothiocyanates [114][115][116][117][118][119][120][121][122]. However, it has also been shown that isothiocyanates produced by Brassica kaber and Brassica nigra inhibit mycorrhizal fungi [123].…”

Manejo de la costra negra de la papa (Rhizoctonia solani) con el establecimiento de abonos verdes

“…De acuerdo a lo expuesto por autores como Manici et al, (2004) y Mazzola (2010), dentro de la microbiota antagónica favorecida se encuentran bacterias como Bacillus, Pseudomonas y especies no patogénicas de Streptomyces, así como el hongo Trichoderma (Yossen et al, 2011), del hay especies con mayor tolerancia frente a isotiocianatos producidos por tejidos incorporados de Brassica, respecto a otros hongos patógenos del suelo (Larkin y Griffin, 2007;Vandicke et al, 2020). En este grupo de plantas, se ha identificado especies de mostaza como Brassica juncea y B. nigra poseen efecto biofumigante contra aislados del patógeno R. solani en papa y hortalizas (Rubayet et al, 2018;Abdallah, Yehia, y Kandil, 2020).…”

“…Se ha demostrado que especies de la familia Brassicaceae poseen componentes naturales como los glucosinolatos, producidos a partir del metabolismo secundario de las plantas que al ser utilizadas como abonos verdes liberan una serie de compuestos tóxicos, en especial la capacidad biofumigante de los isotiocianatos, que limitan directamente el desarrollo hongos patógenos del suelo (Larkin y Griffin, 2007;Vandicke et al, 2020). Dayegamiye et al, (2017), exponen que la incorporación al suelo de cereales como variedades de rápido crecimiento de cebada, avena o trigo, cuyo aporte considerable de biomasa trae consigo efectos positivos sobre las propiedades del suelo y su microbiota; condiciones que predisponen una menor incidencia de fitopatógenos.…”