Association of Morphology and Mycotoxin Production with Vegetative Compatibility Groups in Aspergillus flavus, A. parasiticus, and A. tamarii

Horn, Bruce W.; Greene, Ronald L.; Соболев, В. С.; Dorner, Joe W.; Powell, J. H.; Layton, Robert C.

doi:10.2307/3761151

Cited by 136 publications

(109 citation statements)

References 30 publications

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“…Vegetative incompatibility among strains gives rise to vegetative compatibility groups (VCGs) that limit genetic exchange through the parasexual cycle and may eventually lead to isolation and homogeneity in toxin phenotype [22]. Aflatoxin production and morphology (sclerotium size and number; conidial color) are highly consistent within a given VCG [23]. In contrast, sexual reproduction in A. flavus and A. parasiticus occurs between individuals that belong to different VCGs and often differ in their toxigenicity [14], [16].…”

Section: Introductionmentioning

confidence: 99%

Sexuality Generates Diversity in the Aflatoxin Gene Cluster: Evidence on a Global Scale

et al. 2013

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Aflatoxins are produced by Aspergillus flavus and A. parasiticus in oil-rich seed and grain crops and are a serious problem in agriculture, with aflatoxin B1 being the most carcinogenic natural compound known. Sexual reproduction in these species occurs between individuals belonging to different vegetative compatibility groups (VCGs). We examined natural genetic variation in 758 isolates of A. flavus, A. parasiticus and A. minisclerotigenes sampled from single peanut fields in the United States (Georgia), Africa (Benin), Argentina (Córdoba), Australia (Queensland) and India (Karnataka). Analysis of DNA sequence variation across multiple intergenic regions in the aflatoxin gene clusters of A. flavus, A. parasiticus and A. minisclerotigenes revealed significant linkage disequilibrium (LD) organized into distinct blocks that are conserved across different localities, suggesting that genetic recombination is nonrandom and a global occurrence. To assess the contributions of asexual and sexual reproduction to fixation and maintenance of toxin chemotype diversity in populations from each locality/species, we tested the null hypothesis of an equal number of MAT1-1 and MAT1-2 mating-type individuals, which is indicative of a sexually recombining population. All samples were clone-corrected using multi-locus sequence typing which associates closely with VCG. For both A. flavus and A. parasiticus, when the proportions of MAT1-1 and MAT1-2 were significantly different, there was more extensive LD in the aflatoxin cluster and populations were fixed for specific toxin chemotype classes, either the non-aflatoxigenic class in A. flavus or the B1-dominant and G1-dominant classes in A. parasiticus. A mating type ratio close to 1∶1 in A. flavus, A. parasiticus and A. minisclerotigenes was associated with higher recombination rates in the aflatoxin cluster and less pronounced chemotype differences in populations. This work shows that the reproductive nature of the population (more sexual versus more asexual) is predictive of aflatoxin chemotype diversity in these agriculturally important fungi.

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Section: Introductionmentioning

confidence: 99%

Sexuality Generates Diversity in the Aflatoxin Gene Cluster: Evidence on a Global Scale

et al. 2013

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“…The frequency of detection was 60% for the Caiapó, with mean levels ranging from 304.1 to 2583.7 μg/kg, and 74.3% for the 886, with levels ranging from 288.0 to 4918.1 μg/kg [17]. Other studies investigating the production of CPA in peanuts also reported high rates of 89 [52], 93 [53], and 97% [54]. Alatoxins and CPA were also detected simultaneously in kernel samples (11.4%).…”

Section: Resultsmentioning

confidence: 75%

First Report of Mycotoxins in Second Peanuts Crop in Adana and Osmaniye at Harvest, Drying, Prestorage and Storage Periods

Lavkor¹,

Var²,

Öztemiz³

et al. 2017

Aflatoxin-Control, Analysis, Detection and Health Risks

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Alatoxin (AF) and cyclopiazonic acid (CPA) contaminations are very important problems for peanuts and its products. The aim of the study was to detect alatoxin (types B and G) and cyclopiazonic acid (CPA) occurrence and critical periods of toxin production in peanuts collected from diferent research areas of Osmaniye and Adana, Turkey, in 2015. Peanut kernels toxin analysis was performed in four diferent periods during the harvest, drying, prestorage, and storage. Total alatoxin occurrence in peanut kernels was analyzed by immunoainity chromatography-reversed-phase high-performance liquid chromatography (IAC-HPLC) analysis and cyclopiazonic acid occurrence in peanut kernels was analyzed by thin layer chromatography (TLC). Alatoxin levels in 76 out of 102 contaminated samples were from 0.3 to 1333.42 μg/kg. Cyclopiazonic acid levels in 18 out of 102 peanut samples were from 16.6 to 44.44 μg/kg. An unusual patern of mycotoxin production (alatoxin types B and G simultaneously with CPA) was seen in 11 of 102 peanuts samples. Six of nine samples were from the storage period. Alatoxin contamination during harvesting (64%) and drying (75%) were higher than prestorage (53%). Alatoxin (93%) and cyclopiazonic acid (30%) were the most produced during storage. The results showed that storage period was signiicantly important for the presence of two mycotoxins according to the statistical analysis.

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“…The GenBank accession number for the 18S rRNA sequence of Botryosphaeria laricina JAS6 and Aspergillus tamarii JAS9 isolates were KC509580 and KC509583, respectively. Earlier works have reported that Aspergillus tamarii as an endophyte of Coscinium fenestratum [26] and certain compound like aﬂatoxin [27], fumigaclavine A [28], cyclopiazonic acid [29], kojic and itaconic acids [30] have been produced from Aspergillus tamarii . However, this is the first report on A.tamarii in bioremediation studies.…”

Section: Resultsmentioning

confidence: 99%

Mycoremediation of Endosulfan and Its Metabolites in Aqueous Medium and Soil by Botryosphaeria laricina JAS6 and Aspergillus tamarii JAS9

Silambarasan

Abraham

2013

PLoS ONE

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Microbial degradation offers an efficient and ecofriendly approach to remove toxicants from the contaminated environments. Botryosphaeria laricina JAS6 and Aspergillus tamarii JAS9 were capable of degrading endosulfan and their metabolites which were isolated through enrichment technique. Both the strains were able to withstand an exposure of 1300 mg/L and showed luxuriant growth at 1000 mg/L of endosulfan. The change in pH in the culture broth was from 6.8 to 3.4 and 3.8 during growth kinetic studies of JAS6 and JAS9 strains, respectively upon biological degradation of endosulfan. The degradation of endosulfan by JAS6 and JAS9 strains were examined by HPLC. The biodegradation rate constant (k) and the initial concentration were reduced by 50% (DT50) which was determined by first and pseudo first order kinetic models. In the present investigation it has been revealed that Botryosphaeria laricina JAS6 and Aspergillus tamarii JAS9 possessing endosulfan degrading capability are being reported for the first time. These findings confirm the degradation of endosulfan by JAS6 and JAS9 strains which were accompanied by significant reduction in the toxicity and could be used as remedial measure in contaminated environments.

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Association of Morphology and Mycotoxin Production with Vegetative Compatibility Groups in Aspergillus flavus, A. parasiticus, and A. tamarii

Cited by 136 publications

References 30 publications

Sexuality Generates Diversity in the Aflatoxin Gene Cluster: Evidence on a Global Scale

Sexuality Generates Diversity in the Aflatoxin Gene Cluster: Evidence on a Global Scale

First Report of Mycotoxins in Second Peanuts Crop in Adana and Osmaniye at Harvest, Drying, Prestorage and Storage Periods

Mycoremediation of Endosulfan and Its Metabolites in Aqueous Medium and Soil by Botryosphaeria laricina JAS6 and Aspergillus tamarii JAS9

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