Growth Of Fusarium Verticillioides Research Articles

FvKex2 is required for development, virulence, and mycotoxin production in Fusarium verticillioides

Fusarium verticillioides is one of the most important fungal pathogens causing maize ear and stalk rots, thereby undermining global food security. Infected seeds are usually unhealthy for consumption due to contamination with fumonisin B1 (FB1) mycotoxin produced by the fungus as a virulence factor. Unveiling the molecular factors that determine fungal development and pathogenesis will help in the control and management of the diseases. Kex2 is a kexin-like Golgi-resident proprotein convertase that is involved in the activation of some important proproteins. Herein, we identified and functionally characterized FvKex2 in relation to F. verticillioides development and virulence by bioinformatics and functional genomics approaches. We found that FvKex2 is required for the fungal normal vegetative growth, because the growth of the ∆Fvkex2 mutant was significantly reduced on culture media compared to the wild-type and complemented strains. The mutant also produced very few conidia with morphologically abnormal shapes when compared with those from the wild type. However, the kexin-like protein was dispensable for the male role in sexual reproduction in F. verticillioides. In contrast, pathogenicity was nearly abolished on wounded maize stalks and sugarcane leaves in the absence of FvKEX2 gene, suggesting an essential role of Fvkex2 in the virulence of F. verticillioides. Furthermore, high-performance liquid chromatography analysis revealed that the ∆Fvkex2 mutant produced a significantly lower level of FB1 mycotoxin compared to the wild-type and complemented strains, consistent with the loss of virulence observed in the mutant. Taken together, our results indicate that FvKex2 is critical for vegetative growth, FB1 biosynthesis, and virulence, but dispensable for sexual reproduction in F. verticillioides. The study presents the kexin-like protein as a potential drug target for the management of the devastating maize ear and stalk rot diseases. Further studies should aim at uncovering the link between FvKex2 activity and FB1 biosynthesis genes.Key points•The kexin-like protein FvKex2 contributes significantly to the vegetative growth of Fusarium verticillioides.•The conserved protein is required for fungal conidiation and conidial morphology, but dispensable for sexual reproduction.•Deletion of FvKEX2 greatly attenuates the virulence and mycotoxin production potential of F. verticillioides.

The Role of Mycotoxins in Interactions between Fusarium graminearum and F. verticillioides Growing in Saprophytic Cultures and Co-Infecting Maize Plants.

Fusarium graminearum (FG) and Fusarium verticillioides (FV) co-occur in infected plants and plant residues. In maize ears, the growth of FV is stimulated while FG is suppressed. To elucidate the role of mycotoxins in these effects, we used FG mutants with disrupted synthesis of nivalenol (NIV) and deoxynivalenol (DON) and a FV mutant with disrupted synthesis of fumonisins to monitor fungal growth in mixed cultures in vitro and in co-infected plants by real-time PCR. In autoclaved grains as well as in maize ears, the growth of FV was stimulated by FG regardless of the production of DON or NIV by the latter, whereas the growth of FG was suppressed. In autoclaved grains, fumonisin-producing FV suppressed FG more strongly than a fumonisin-nonproducing strain, indicating that fumonisins act as interference competition agents. In co-infected maize ears, FG suppression was independent of fumonisin production by FV, likely due to heterogeneous infection and a lower level of fumonisins in planta. We conclude that (i) fumonisins are agents of interference competition of FV, and (ii) trichothecenes play no role in the interaction between FG and FV. We hypothesize the following: (i) In vitro, FG stimulates the FV growth by secreting hydrolases that mobilize nutrients. In planta, suppression of plant defense by FG may additionally play a role. (ii) The biological function of fumonisin production in planta is to protect kernels shed on the ground by accumulating protective metabolites before competitors become established. Therefore, to decipher the biological function of mycotoxins, the entire life history of mycotoxin producers must be considered.

Bio rational green approaches for effective management of post flowering stalk rot in maize (Zea mays)

Present study was carried out to assess efficacy of bio agents and organic ITK’s against post flowering stalk rot at Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan during 2019–20. The results of in vitro studies revealed that Trichoderma viride (65%) significantly inhibited the mycelium growth of Fusarium verticillioides. In field conditions, T. viride showed low disease rating 3.0, low per cent disease incidence (25.20%) and high efficacy of disease control (62.27%) with good grain yield 1191 g/plot against the pathogen at 2% concentrations. Maize growers can protect their crop from this disease by using the sustainable, environmentally friendly disease control strategies that were found in our study.

Synthesis, characterization and fungicidal activity of novel 2-aminopyrimidine Schiff bases

2-Aminopyrimidines represents vital class of bioactive molecules where its structural changes would lead to its peculiar properties. N -heterocyclic compound i.e. 2-aminopyrimidine had wide range of applications in pharmacological, material chemistry and agriculture as antifungal, antimicrobial and antibacterial agents. 2-Aminopyrimidine and its derivatives are good candidates for antimicrobial, antifungal and anticorrosion activity. In the present study, a series of substituted N -benzylidine-2-aminopyrimidine compounds have been synthesized by condensation reaction of 2-aminopyrimidine with substituted benzaldehydes ( o -chloro , m -hydroxybenzaldehyde, p -hydroxybenzaldehyde, 2,5-dimethoxybenzaldehyde, p -dimethylaminobenzaldehye, syringaldehyde, o -phthaldehyde, isovanillin benzaldehyde, veratraldehyde and thiophene-2-carboxyaldehyde) using glacial acetic acid or NaOH (40%). The synthesised Schiff bases have been characterized using UV, IR, 1 H NMR and 13 C spectral studies. 2-Aminopyrimidine Schiff bases ( 1-10 ) have been examined for fungitoxicity on the growth of Fusarium verticillioides , Rhizoctonia solani and Macrophomina phaseolina using poisoned food technique.

Roles of the MYB94/FUSED LEAVES1 (ZmFDL1) and GLOSSY2 (ZmGL2) genes in cuticle biosynthesis and potential impacts on Fusarium verticillioides growth on maize silks.

Maize silks, the stigmatic portions of the female flowers, have an important role in reproductive development. Silks also provide entry points for pathogens into host tissues since fungal hyphae move along the surface of the silks to reach the site of infection, i.e., the developing kernel. The outer extracellular surface of the silk is covered by a protective hydrophobic cuticle, comprised of a complex array of long-chain hydrocarbons and small amounts of very long chain fatty acids and fatty alcohols. This work illustrates that two previously characterized cuticle-related genes separately exert roles on maize silk cuticle deposition and function. ZmMYB94/FUSED LEAVES 1 (ZmFDL1) MYB transcription factor is a key regulator of cuticle deposition in maize seedlings. The ZmGLOSSY2 (ZmGL2) gene, a putative member of the BAHD superfamily of acyltransferases with close sequence similarity to the Arabidopsis AtCER2 gene, is involved in the elongation of the fatty acid chains that serve as precursors of the waxes on young leaves. In silks, lack of ZmFDL1 action generates a decrease in the accumulation of a wide number of compounds, including alkanes and alkenes of 20 carbons or greater and affects the expression of cuticle-related genes. These results suggest that ZmFDL1 retains a regulatory role in silks, which might be exerted across the entire wax biosynthesis pathway. Separately, a comparison between gl2-ref and wild-type silks reveals differences in the abundance of specific cuticular wax constituents, particularly those of longer unsaturated carbon chain lengths. The inferred role of ZmGL2 is to control the chain lengths of unsaturated hydrocarbons. The treatment of maize silks with Fusarium verticillioides conidia suspension results in altered transcript levels of ZmFDL1 and ZmGL2 genes. In addition, an increase in fungal growth was observed on gl2-ref mutant silks 72 hours after Fusarium infection. These findings suggest that the silk cuticle plays an active role in the response to F. verticillioides infection.

Management of Major Seed-Borne Fungi of Cowpea (Vigna unguiculata (L.) Walp) with Four Selected Botanical Extracts

Seed-borne fungal pathogens present significant constrain to the production and conservation of many seed crops including cowpea. Infection of mature seeds by such pathogens could result in mycotoxin contamination, loss of viability, and decay of seeds. This study aimed to identify seed-borne fungi on 200 accessions of cowpea under cold storage at CSIR-Plant Genetic Resources Research Institute (PGRRI), Ghana. Also, the antifungal effect of seeds of Piper nigrum, Xylopia aethiopica, Aframomum melegueta, and fresh leaves of Cymbopogon citratus aqueous extracts (100% w/v) on the major seed-borne fungi identified on the cowpea seeds was determined. Seven fungal species belonging to five genera were identified from the seeds of the cowpea accessions evaluated. However, the diversity and infection levels of the pathogenic fungi recorded on the seeds were lower than that of the saprophytic fungi indicating minimal capacity of the seeds to spread pathogenic fungi on the field. Aqueous extract of Aframomum melegueta inhibited the growth of Fusarium verticillioides by 98.40%, Colletotrichum sp. by 97.83%, Aspergillus niger by 94.70%, and Aspergillus flavus by 63.38%. The only other aqueous extract that inhibited the colony growth above 60% was that of Piper nigrum which inhibited colony growth of Fusarium verticillioides by 71.7% and Colletotrichum sp. by 63.47%. Due to the benign effect of Aframomum melegueta extract on the environment and non-target organisms, its use as a seed protectant is highly recommended. Further studies to establish the spectrum of activity and dose levels of Aframomum melegueta extract are recommended.

Bacillomycin D-C16 inhibits growth of Fusarium verticillioides and production of fumonisin B1 in maize kernels

Fusarium verticillioides causes ear and kernel rot in maize and produces mycotoxins, like fumonisin B1 (FB1). Bacillomycin D-C16 is a natural antimicrobial lipopeptide produced by Bacillus subtilis. In this study, the inhibitory effects of Bacillomycin D-C16 on the growth of F. verticillioides and on the production of FB1 in maize were investigated. Bacillomycin D-C16 displayed strong fungicidal activity against F. verticillioides, with a minimum inhibitory concentration (MIC) of 32 g/L. Scanning electron microscopy (SEM) showed that Bacillomycin D-C16 altered the morphology of F. verticillioides mycelia. Bacillomycin D-C16 reduced the ergosterol content, increased the release of nucleic acids and proteins, and increased the levels of reactive oxygen species (ROS) in fungal mycelia. Bacillomycin D-C16 also significantly inhibited the production of FB1 by inhibiting mycelial growth and decreasing the levels of fumonisin biosynthetic genes 1 (fum1), fum6 and fum14. The application of Bacillomycin D-C16 on maize kernels prior to storage inhibited the growth of F. verticillioides and the production of FB1. Our results suggested that Bacillomycin D-C16 has a significant antifungal activity that could be used as a potential natural antimicrobial agent to control food contamination and to ensure food safety.

Effects of the volatile organic compounds produced by Enterococcus spp. strains isolated from maize grain silos on Fusarium verticillioides growth and fumonisin B1 production

Fusarium verticillioides is a phytopathogenic fungus that can contaminate maize grain silos and result in important losses in the post-harvest product. The objective of this work was to investigate the effects of volatile organic compounds produced by four lactic acid bacterial strains isolated from maize grain silos on F. verticillioides M3125 growth and fumonisin B1 (FB1) production. The bacterial isolates 55 and 49 were identified as Enterococcus faecium and M4A and M4G as Enterococcus casseliflavus. The fungal growth was inhibited by 33.33% by the volatiles released by the M4A strain and by approximately 10% by the volatiles emitted by the 55 and 49 strains. The volatiles produced by the M4A strain also significantly reduced (88.75%) FB1 biosynthesis. The gas chromatography–mass spectrometer analysis identified 21 volatile organic compounds, with diacetyl, acetic acid and acetoin being the main volatiles emitted by the four bacterial strains. Acetoin was the volatile produced in the highest proportion by the four strains, with M4A generating the highest proportion of diacetyl (35.11%). Diacetyl and acetic acid completely inhibited fungal growth at concentrations of 0.3 and 1 mM, respectively, while acetoin promoted fungal growth. Only acetoin significantly reduced FB1 production. These results showed that diacetyl was the main compound involved in fungal inhibition, while the effect on FB1 production could have been due to the combination of the volatile organic compounds produced by the M4A strain. In conclusion, the volatiles emitted by the E. casseliflavus M4A strain could be a promising tool for the biocontrol of F. verticillioides in storage maize grain silos.

Physical and chemical parameters, Fusarium verticillioides growth and fumonisin production in kernels of nine maize genotypes

Fusarium verticilloides synthesizes fumonisins (FBs) in the field and during faulty storage of maize. FBs are worrisome because of their toxicological effects. Nine maize genotypes differing in physical grain properties, phytochemical profiles, and chemical compositions were evaluated. Kernels were tempered to 18% moisture and purposely contaminated with F. verticilloides to assess differences in mold growth and FBs. The genotype significantly influenced counts with mean values ranging from 12.9 CFU/mLx104 for the highly susceptible Blue Don Goyo to only 1.0 CFU/mLx104 for the Pob84C3 genotype. The concentrations of FBs in these two genotypes were 6.85 and 0.3 ppm, respectively. Popcorn kernels showed a relatively high level of Fusarium counts (7.0 CFU/mLx104) but low concentrations of FBs (1.4 ppm). The large-sized Cacahuacintle and Don Goyo kernels, which had the lowest test weights and highest 1000 kernel weight (TKW) showed the highest occurrence of CFU likely due to their low proportion of pericarp, bound phenolics (coumaric), diferulic acids and bound antioxidants. Correlations indicated that mold counts did not correlate (r2 = 0.6, P = 0.08) with FBs. However, grain thickness, hardness, TKW and bound phenolics were related to Fusarium counts. This research demonstrated that contrasting maize genotypes showed different susceptibilities to Fusarium growth and FBs contamination.

Proteomic analysis of the inhibitory effect of the butanolic fraction of Jacquinia macrocarpa on Fusarium verticillioides.

Jacquinia macrocarpa, a plant native to northwestern Mexico, has an inhibitory effect against phytopathogenic fungi. Previous studies have shown that the butanolic extract of J. macrocarpa causes retardation and atrophy in mycelial growth of Fusarium verticillioides. However, the action mechanism of this extract is unknown. We used a proteomics approach to understand the inhibitory effect of J. macrocarpa butanolic extract, based on differential protein accumulation in F. verticillioides. Proteins were extracted from F. verticillioides cultured in Czapek broth with and without 202.12 μg/mL (IC50) of butanolic extract of J. macrocarpa. Thirty-eight protein spots showing statistically significant changes (ANOVA, p < 0.01) and at least a 2-fold change in abundance between experimental conditions were analyzed by mass spectrometry. Identified proteins were grouped into different biological processes according to Gene Ontology, among them were amino acid metabolism, protein folding and stabilization, protein degradation, protein transport, carbohydrate metabolism, oxidative stress response, and miscellaneous. This work is the first report of changes in the proteomic profile of F. verticillioides exposed to the J. macrocarpa extract. This information provides new insights into the inhibitory mechanism of the extract and represents a starting point for dissection of the fungal response against the J. macrocarpa extract components.

Bioactive Compounds Obtained from Oilseed By-Products with Subcritical Fluids: Effects on Fusarium verticillioides Growth

Recovery of bioactive compounds from wastes is gaining interest because they could add value to by-products arising from, for example, the oil extraction processes. In this work, green solvent extraction (water/ethanol under sub-critical conditions) was used to obtain bioactive compounds from peanut, sesame and pistachio agro-industrial by-products. Extracts were analyzed in their overall chemical composition and tested on growth, ergosterol and fumonisin FB1 production by Fusarium verticillioides. The effects of the extracts on fungal growth rate and biochemical markers were not univocal, and could be associated to differences in their chemical profiles. Extracts obtained from peanut skin—composed mainly by monomeric and dimeric flavonoids—caused significant reductions in fungal growth rate but increased FB1 production. Extracts from sesame seeds—dominated by furofuran-type lignans—did not have a clear inhibitory effect on growth rate but strongly reduced both FB1 and ergosterol production. Extracts from pistachio nuts—characterized by monomeric flavonoids and gallic acid derivatives—showed minor effects on both fungal growth rate and biochemical markers. Sub-critical fluid extraction of peanut skin and defatted sesame seeds may provide an efficient method to obtain extracts rich in phenolic and lignan compounds with potential use as antifungal agents.

Evaluation of phyllosphere antagonistic bacteria on the management of Fusarium ear rot of maize caused by Fusarium verticillioides

Fusarium verticillioides is an insidious fungal pathogen of maize associated with diseases such as ear rot and kernel rot. It attacks the phyllosphere region of the maize plant especially on inflorescence and cobs. Thus, this study was conducted to isolate potential phyllosphere colonizing antagonistic microbes for the management of Fusarium ear rot. Four phyllosphere colonizing antagonistic bacteria were found to be effective in suppression of the growth of Fusarium verticillioides . Based on 16S rDNA analysis, these bacterial isolates were identified as Pseudomonas aeruginosa isolate 1, P. aeruginosa isolate 2, Bacillus subtilis isolate and B. amyloliquefaciens . Among these four phyllosphere bacteria tested against F. verticillioides , the maximum inhibition of mycelial growth of F. verticillioides and production of volatile compounds was exhibited by P. aeruginosa isolate 1. Application of P. aeruginosa isolate -1, as seed treatment @ 10 g/kg of seeds, soil application @ 5 g/pot and foliar spray @ 0.2 per cent, recorded the minimum PDI with the maximum disease reduction over control. Thus, the present study showed that P. aeruginosa isolated from agricultural ecosystem could be a potential phyllosphere antagonistic bacterium for the management of maize ear rot disease.

Trichoderma asperellum isolated from African maize seed directly inhibits Fusarium verticillioides growth in vitro

Maize is a globally important crop that is affected by fungal diseases causing yield losses annually. One fungus, Fusarium verticillioides, causes the disease Fusarium Ear Rot (FER), which reduces grain quality and produces mycotoxins called fumonisins that are harmful to animals and humans. As chemical fungicides are expensive and have negative environmental effects, the use of biological control agents (BCAs) has become favourable in recent years. A commonly used fungal BCA is Trichoderma spp., which has been effective in reducing disease incidence as well as enhancing crop growth. In this study, T. asperellum was isolated from an African maize line and was shown to significantly inhibit growth of F. verticillioides in an in vitro competition assay.

Essential oils as an alternative postharvest treatment to control fusariosis, caused by Fusarium verticillioides , in fresh pineapples ( Ananas comosus )

Abstract Fusariosis of the pineapple is an aggressive disease which needs to be controlled during postharvest. Essential oils have been studied with the intention of incorporating them into integrated pest management, to avoid or reduce the use of synthetic fungicides. In-vitro assays showed that thyme oil was the best essential oil for controlling mycelial growth of Fusarium verticillioides. Because of its fungicidal effect, four concentrations of thyme oil (100, 250, 500 and 1000 μL L−1) were tested in-vivo. The results showed that after 21 d at 8 °C plus 7 d of shelf-life at 20 °C, the reduction of the severity of F. verticillioides on pineapples treated with 1000 μL L−1 of thyme oil (50.1%) was higher (p

Biocontrol of Fusarium verticillioides using organic amendments and their actinomycete isolates

In a sustainable development concern, the agricultural practices notably those to control the pathogenic and/or mycotoxigenic fungi that maintain the quality and the abundance of crops with respecting the ecosystems and public health are indispensable. Our study focuses on evaluating the biocontrol potential of the actinomycete microflora of some organic amendments against the phytopathogenic and mycotoxigenic Fusarium verticillioides. The inhibitory effect was assessed in term of growth and mycotoxin production (fumonisin FB1 and FB2) of F. verticillioides in the presence of amended soils and selected antagonist agents from the amendments.Results demonstrated that the amended soils with different organic amendments exhibited a higher inhibition rate of Fusarium verticillioides growth than the reference soil. They were able to inhibit the fungal pigment and spore productions which are the major mean of survival and dispersion of this fungus. The fumonisin production was strongly reduced by the metabolites produced by the amended soils’ microbiota, up to 68.7% and 92.5% for FB1 and FB2 respectively. Actinomycete strains isolated from these amendments were identified as Streptomyces and were also tested for their antifungal potential. The fungal growth was reduced up to more than 60% in the presence of extracellular metabolites of several Streptomyces strains. In confrontation assays, most of the Streptomyces strains inhibited strongly both fungal growth and fumonisin production. The FB1 and FB2 amounts were decreased at best, by up to 87.5% and 98.2% respectively, depending on the actinomycete strains and fungal culture time. These results are promising for the use of these biocontrol agents, and especially some actinomycete strains, as tools to reduce fumonisin contamination in cereal crops and derived products.

Isolation, Identification and Usefulness of Antifungal Compounds from Zuccagnia punctata for Control of Toxigenic Ear Rot Pathogens

Infusion, tincture and decoction of leaves of Zuccagnia punctata Cav. were assayed on growth of Fusarium verticillioides, F. graminearum sensu stricto, F. boothii, F. meridionale, F. subglutinans and F. thapsinum. The tincture showed the lowest IC50 on mycelial growth. A diethyl ether fraction of the tincture showed the highest antifungal activity in microdilution assays on F. verticillioides and F. graminearum. The antifungal constituents were separated by silica gel chromatography and identified as 2',4'-dihydroxychalcone, 2',4'-dihydroxy-3'-methoxychalcone and 7-hydroxy-3',4'-dimethoxyflavone. These chalcones had the lowest MIC and MFC values on F. verticillioides and F. graminearum sensu stricto. 2',4'-Dihydroxychalcone was mildly toxic and the remaining identified compounds were non-toxic in the brine shrimp assay. 2',4'-Dihydroxychalcone in mixtures with commercial food preservatives showed additive effects on F. graminearum sensu stricto and synergistic ones on F. verticillioides. 2',4'-Dihydroxy-3'-methoxychalcone showed synergistic effects in mixtures. Our results suggest that addition of chalcones to food preservatives allows reduction in the doses of the preservatives required for control of Fusarium species.

English

The efficacy of some botanicals and bio-agents were assessed in vitro as the potential biofungicides against Fusarium verticillioides, the causal organism of stalk rot disease of maize plant. The botanicals used in this study were Morinda lucida (Oruwo) and Tithonia diversifolia (Mexican Sunflower) and the bio-agents used were Trichoderma viride, Trichoderma harzianum, Trichoderma pseudokoningii and Bacillius subtilis. All the plant extracts and antagonistic organisms significantly inhibited the growth of Fusarium verticillioides. However, out of the antagonists, T. viride provided the highest inhibitory effect followed by T. pseudokoningii, T. harzianum, and B. subtilis which was the lowest suppressive antagonist. The extract from T. diversifolia, provided the highest inhibitory effect followed by M. lucida. Key words: Maize, ear rot, botanicals, bioagents, Fusarium verticillioides.

Antifungal activity and inhibition of fumonisin production by Rosmarinus officinalis L. essential oil in Fusarium verticillioides (Sacc.) Nirenberg

The chemical composition of Rosmarinus officinalis L. essential oil (REO) was analysed by gas chromatography–mass spectrometry and nuclear magnetic resonance spectroscopy. The main compounds of the REO were 1.8 cineole (52.2%), camphor (15.2%) and α-pinene (12.4%). The mycelial growth of Fusarium verticillioides (Sacc.) Nirenberg was reduced significantly by 150μg/mL of REO. Significant microscopic morphological changes were visualised, such as the rupture of the cell wall and the leakage of cytoplasm at 300μg/mL of REO. At lower concentrations of REO, the effects on the production of ergosterol and the biomass of mycelium varied, as did the effects on the production of fumonisins, but at ⩾300μg/mL of REO, these processes were significantly inhibited, showing the effectiveness of the REO as an antifungal agent. The results suggested that the REO acts against F. verticillioides by disrupting the cell wall and causing the loss of cellular components, subsequently inhibiting the production of fumonisins and ergosterol.

Activity of natural compounds from peanut skins on Fusarium verticillioides growth and fumonisin B1 production

The objectives of this investigation were to evaluate the antifungal and antimycotoxigenic properties of peanut skin extracts (PSE) against Fusarium verticillioides. The PSE were prepared by a multisolvent extraction procedure, and the activity on growth parameters and fumonisin B1 (FB1) production of the three PSE was explored at different concentrations on potato dextrose agar and in artificially infected maize kernels, respectively. The results demonstrated that all PSE had a significant influence on growth rate or lag phase of F. verticillioides. The yellow and purple (250–500μgml−1) extracts decreased growth rate, whereas brown extract extended the lag phase. Only the yellow extract at 62.5μgml−1 was able to affect both growth rate and lag phase. With respect to mycotoxin production a significant stimulation on FB1 production was observed with purple (62.5μgml−1) and brown (250μgml−1) extracts. In contrast, a significant decreased in FB1 was observed at 62.5μgml−1 of yellow extract. These findings showed that natural compounds from PSE possess inhibitory effects on F. verticillioides growth and mycotoxin production. Thus, PSE could be use as an alternative to minimize fungal contamination.

Inhibitory effect of 10 natural phenolic compounds on Fusarium verticillioides. A structure–property–activity relationship study

Fusarium is a ubiquitous hyalohyphomycete fungus usually isolated from food, which is widespread in different environments (plant, grain, soil) and present at all latitudes. This genus has been widely studied due to its ability to infect, cause tissue destruction and produce mycotoxins on important crops such as corn, wheat and other small grains. Over recent years, much effort has been directed at the search for new antifungal materials from natural sources, and many antimicrobial compounds coming from plants have been identified. Although the essential oils and their components have been recommended as fumigants for preservation of food commodities, little is known about the molecular properties related to the antifungal activity. In the present study, we performed a QSAR study for the inhibition of Fusarium verticillioides growth by ten natural phenolic compounds, which could serve as a guide for the rational design of further inhibitors. The results of the experimental determinations demonstrated that in terms of the antifungal activity of natural phenolic compounds on F. verticillioides, the following order was found: carvacrol > thymol > isoeugenol > eugenol > vanillin > creosol > m-cresol > o-cresol, p-cresol, and guaiacol. Mathematical models based on molecular properties, Lipophilicity, Molar refractivity and Saturated area were found to be the descriptors that best explained the antifungal activity of these compounds. These models could be used in future to predict the activity of new compounds and to guide the search for the synthesis of phenolic compounds with the capacity to alter F. verticillioides growth.