scholarly journals Molecular Identification and Mycotoxin Production by Alternaria Species Occurring on Durum Wheat, Showing Black Point Symptoms

Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 275 ◽  
Author(s):  
Mario Masiello ◽  
Stefania Somma ◽  
Antonia Susca ◽  
Veronica Ghionna ◽  
Antonio Francesco Logrieco ◽  
...  

Black point is a fungal disease of wheat, mainly associated with mycotoxigenic Alternaria species. Affected wheat kernels are characterized by dark brown discolouration of the embryo region and reduction of grain quality. Potential risk is the possible accumulation of Alternaria mycotoxins, alternariol (AOH), alternariol-monomethyl ether (AME), tenuazonic acid (TA), and altenuene (ALT), provided by haemato-toxic, genotoxic, and mutagenic activities. One hundred and twenty durum wheat samples belonging to 30 different genotypes grown in Bologna and Modena areas, in Italy, showing black point symptoms, were analyzed for Alternaria species and their mycotoxin contamination. Alternariol was selected as an indicator of the capability of the Alternaria species to produce mycotoxin in vivo in field conditions. The data showed that Alternaria species occurred in 118 out of 120 wheat kernels samples, with the incidence of infected kernels ranging between 1% and 26%. Moreover, AOH was detected by using a HPLC with a diode array detector (LC-DAD) in 98 out of 120 samples with values ranging between 24 and 262 µg Kg−1. Ninety-two Alternaria representative strains, previously identified morphologically, were identified at species/section level using gene sequencing, and therefore were analyzed for their mycotoxin profiles. Eighty-four strains, phylogenetically grouped in the Alternaria section, produced AOH, AME, and TA with values up to 8064, 14,341, and 3683 µg g−1, respectively, analyzed by using a LC-DAD. On the other hand, eight Alternaria strains, included in Infectoriae Section, showed a very low or no capability to produce mycotoxins.

2008 ◽  
Vol 71 (6) ◽  
pp. 1262-1265 ◽  
Author(s):  
M. P. AZCARATE ◽  
A. PATRIARCA ◽  
L. TERMINIELLO ◽  
V. FERNÁNDEZ PINTO

The natural occurrence of Alternaria mycotoxins in Argentinean wheat from the zone 5 South during the 2004 to 2005 harvest was investigated in 64 wheat samples. All samples were highly contaminated with a wide range of fungal species. Alternaria was found as the main component of the mycota, with an infection percentage of 100%. Three mycotoxins produced by species of Alternaria were determined in wheat: alternariol, alternariol monomethyl ether, and tenuazonic acid. Alternariol was detected in 4 (6%) of 64 samples, with a range of 645 to 1,388 μg/kg (mean of 1,054 μg/kg); alternariol monomethyl ether, with a range of 566 to 7,451 μg/kg (mean of 2,118 μg/kg) in 15 (23%) of 64 samples; and tenuazonic acid in 12 (19%) of 64 samples, with a range of 1,001 to 8,814 μg/kg (mean, 2,313 μg/kg). Alternariol monomethyl ether was the predominant toxin, but tenuazonic acid was detected in higher concentrations. Alternariol was present in fewer samples and in lower levels than were the other toxins. Tenuazonic acid and alternariol monomethyl ether occurred together in four samples, while tenuazonic acid and alternariol co-occurred in one sample. This the first report of the natural occurrence of Alternaria mycotoxins in Argentinean wheat. Toxin levels were high, probably due to the heavy infection with Alternaria species found in the samples.


Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 472 ◽  
Author(s):  
Francesca Ramires ◽  
Mario Masiello ◽  
Stefania Somma ◽  
Alessandra Villani ◽  
Antonia Susca ◽  
...  

Wheat, the main source of carbohydrates worldwide, can be attacked by a wide number of phytopathogenic fungi, included Alternaria species. Alternaria species commonly occur on wheat worldwide and produce several mycotoxins such as tenuazonic acid (TA), alternariol (AOH), alternariol-monomethyl ether (AME), and altenuene (ALT), provided of haemato-toxic, genotoxic, and mutagenic activities. The contamination by Alternaria species of wheat kernels, collected in Tuscany, Italy, from 2013 to 2016, was evaluated. Alternaria contamination was detected in 93 out of 100 field samples, with values ranging between 1 and 73% (mean of 18%). Selected strains were genetically characterized by multi-locus gene sequencing approach through combined sequences of allergen alt1a, glyceraldeyde-3-phosphate dehydrogenase, and translation elongation factor 1α genes. Two well defined groups were generated; namely sections Alternaria and Infectoriae. Representative strains were analyzed for mycotoxin production. A different mycotoxin profile between the sections was shown. Of the 54 strains analyzed for mycotoxins, all strains included in Section Alternaria produced AOH and AME, 40 strains (99%) produced TA, and 26 strains (63%) produced ALT. On the other hand, only a very low capability to produce both AOH and AME was recorded among the Section Infectoriae strains. These data show that a potential mycotoxin risk related to the consumption of Alternaria contaminated wheat is high.


2009 ◽  
Vol 2 (2) ◽  
pp. 129-140 ◽  
Author(s):  
A. Logrieco ◽  
A. Moretti ◽  
M. Solfrizzo

The genus Alternaria includes both plant-pathogenic and saprophytic species, which may affect crops in the field or cause harvest and postharvest decay of plant products. The taxonomy of the genus Alternaria is not well-defined yet. A polyphasic approach based on morphological features, phylogeny and toxin profiles could be the key to a correct identification at species level and the evaluation of mycotoxin risks associated with fungal contamination. Species of Alternaria are known to produce many metabolites, mostly phytotoxins, which play an important role in the pathogenesis of plants. However, certain species, in particular the most common one A. alternata, are capable of producing several mycotoxins in infected plants and/or in agricultural commodities. The major Alternaria mycotoxins belong to three structural classes: the tetramic acid derivative, tenuazonic acid; the dibenzopyrone derivatives, alternariol, alternariol monomethyl ether and altenuene; and the perylene derivatives, the altertoxins. The toxic effects of the Alternaria toxins have not yet received the same attention as the biological activities of other mycotoxins. However, the Alternaria mycotoxins should not be underestimated since they are produced by several Alternaria species frequently associated with a wide range of diseases in many plants of a high agrifood value. The major problems associated with Alternaria mycotoxin contamination of agricultural products are illustrated by focusing on various crops and their relevant diseases, e.g. black rot of tomato, olive, and carrots; black and grey rot of citrus fruits; black point of small-grain cereals; and Alternaria diseases of apples.


2021 ◽  
Vol 7 (3) ◽  
pp. 172
Author(s):  
Francesco Aloi ◽  
Mario Riolo ◽  
Simona Marianna Sanzani ◽  
Annamaria Mincuzzi ◽  
Antonio Ippolito ◽  
...  

This study was aimed at identifying Alternaria species associated with heart rot disease of pomegranate fruit in southern Italy and characterizing their mycotoxigenic profile. A total of 42 Alternaria isolates were characterized. They were obtained from pomegranate fruits with symptoms of heart rot sampled in Apulia and Sicily and grouped into six distinct morphotypes based on macro- and microscopic features. According to multigene phylogenetic analysis, including internal transcribed spacer (ITS), translation elongation factor 1-α (EF-1α), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a SCAR marker (OPA10-2), 38 isolates of morphotypes 1 to 5 were identified as Alternaria alternata, while isolates of morphotype 6, all from Sicily, clustered within the Alternaria arborescens species complex. In particular, isolates of morphotype 1, the most numerous, clustered with the ex-type isolate of A. alternata, proving to belong to A. alternata. No difference in pathogenicity on pomegranate fruits was found between isolates of A. alternata and A. arborescens and among A. alternata isolates of different morphotypes. The toxigenic profile of isolates varied greatly: in vitro, all 42 isolates produced tenuazonic acid and most of them other mycotoxins, including alternariol, alternariol monomethyl ether, altenuene and tentoxin.


2021 ◽  
Vol 11 (9) ◽  
pp. 4239
Author(s):  
Nesrine H. Youssef ◽  
Sameer H. Qari ◽  
Said I. Behiry ◽  
Eldessoky S. Dessoky ◽  
Ehab I. El-Hallous ◽  
...  

Alternaria species, mainly air-borne fungi, affect potato plants, causing black spots symptoms. Morphological identification, pathogenicity assessment, and internal transcribed spacer (ITS) molecular identification confirmed that all isolates were Alternaria alternata. The annotated sequences were deposited in GenBank under accession numbers MN592771–MN592777. HPLC analysis revealed that the fungal isolates KH3 (133,200 ng/g) and NO3 (212,000 ng/g) produced higher levels of tenuazonic acid (TeA) and alternariol monomethyl ether (AME), respectively. Beet ethanol extract (BEE) and beet methanol extract (BME) at different concentrations were used as antimycotoxins. BME decreased the production of mycotoxins by 66.99–99.79%. The highest TeA reduction rate (99.39%) was reported in the KH3 isolate with 150 µg/mL BME treatment. In comparison, the most effective AME reduction rate (99.79%) was shown in the NO3 isolate with 150 µg/mL BME treatment. In the same way, BEE application resulted in 95.60–99.91% mycotoxin reduction. The highest TeA reduction rate (99.91%) was reported in the KH3 isolate with 150 µg/mL BEE treatment, while the greatest AME reduction rate (99.68%) was shown in the Alam1 isolate with 75 µg/mL BEE treatment. GC-MS analysis showed that the main constituent in BME was the antioxidant compound 1-dodecanamine, n,n-dimethyl with a peak area of 43.75%. In contrast, oxirane, methyl- (23.22%); hexadecanoic acid, methyl ester (10.72%); and n-hexadecanoic acid (7.32%) were the main components in BEE found by GC-MS. They are probably antimicrobial molecules and have an effect on the mycotoxin in general. To our knowledge, this is the first study describing the antimycotoxigenic activity of beet extracts against A. alternata mycotoxins-contaminated potato crops in Egypt, aimed to manage and save the environment.


2008 ◽  
Vol 1 (2) ◽  
pp. 175-188 ◽  
Author(s):  
V. Ostry

Microfungi of the genus Alternaria are ubiquitous pathogens and saprophytes. Many species of the genus Alternaria commonly cause spoilage of various food crops in the field or post-harvest decay. Due to their growth even at low temperatures, they are also responsible for spoilage of these commodities during refrigerated transport and storage. Several Alternaria species are known producers of toxic secondary metabolites - Alternaria mycotoxins. A. alternata produces a number of mycotoxins, including alternariol, alternariol monomethyl ether, altenuene, altertoxins I, II, III, tenuazonic acid and other less toxic metabolites. Tenuazonic acid is toxic to several animal species, e.g. mice, chicken, dogs. Alternariol, alternariol monomethyl ether, altenuene and altertoxin I are not very acutely toxic. There are several reports on the mutagenicity and genotoxicity of alternariol, and alternariol monomethyl ether. Alternariol has been identified as a topoisomerase I and II poison which might contribute to the impairment of DNA integrity in human colon carcinoma cells. Analytical methods to determine Alternaria toxins are largely based on procedures, involving cleanup by solvent partitioning or solid phase extraction, followed by chromatographic separation techniques, in combination with ultraviolet, fluorescence, electrochemical and mass spectroscopic detection. A large number of Alternaria metabolites has been reported to occur naturally in food commodities (e.g. fruit, vegetables, cereals and oil plants). Alternariol, alternariol monomethyl ether and tenuazonic acid were frequently detected in apples, apple products, mandarins, olives, pepper, red pepper, tomatoes, tomato products, oilseed rape meal, sunflower seeds, sorghum, wheat and edible oils. Alternariol and alternariol monomethyl ether were detected in citrus fruit, Japanese pears, prune nectar, raspberries, red currant, carrots, barley and oats. Alternariol monomethyl ether and tenuazonic acid were detected in melon. Natural occurrence of alternariol has been reported in apple juice, cranberry juice, grape juice, prune nectar, raspberry juice, red wine and lentils.


Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 883
Author(s):  
Luis G. Addante-Moya ◽  
Antonio Abad-Somovilla ◽  
Antonio Abad-Fuentes ◽  
Consuelo Agulló ◽  
Josep V. Mercader

Immunochemical methods for mycotoxin analysis require antigens with well-defined structures and antibodies with outstanding binding properties. Immunoreagents for the mycotoxins alternariol and/or alternariol monomethyl ether have typically been obtained with chemically uncharacterized haptens, and antigen conjugates have most likely been prepared with mixtures of functionalized molecules. For the first time, total synthesis was performed, in the present study, to obtain two haptens with opposite linker attachment locations. The functionalized synthetic haptens were purified and deeply characterized by different spectrometric methods, allowing the preparation of bioconjugates with unequivocal structures. Direct and indirect competitive enzyme-linked immunosorbent assays, using homologous and heterologous conjugates, were employed to extensively evaluate the generated immunoreagents. Antibodies with high affinity were raised from conjugates of both haptens, and a structure-activity relationship between the synthetic haptens and the specificity of the generated antibodies could be established. These results pave the way for the development of novel highly sensitive immunoassays selective of one or two of these Alternaria mycotoxins.


2021 ◽  
Vol 104 (3) ◽  
pp. 153-162
Author(s):  
Alexandra Stanislavovna Orina* ◽  
Olga Pavlovna Gavrilova ◽  
Tatyana Yuryevna Gagkaeva ◽  
Nadezhda Nikolayevna Gogina

The ubiquitous occurrence of Alternaria fungi belonging to sections Alternaria and Infectoriae was confirmed using real-time PCR in wheat, barley and oat grain grown in West Siberia in 2018‒2019. The DNA amount of Alternaria section Alternaria fungi varied from 53×10-4 to 21731×10-4 pg/ng and on average exceeded the DNA amount of Alternaria section Infectoriae fungi by 4.5‒14.6 times, depending on the crop and harvest year.The average DNA amount of Alternaria fungi belonging to both sections in the oat grain was lower than in wheat and barley grain. The grain samples from Altay region were the most infected with Alternaria fungi. The alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), and tenuazonic acid (TeA) mycotoxins produced by Alternaria fungi were detected by HPLC-MS/MS in 23 %, 6 %, 85 %, and 83 % of analyzed grain samples, respectively. The majority (61 %) of the samples contained two Alternaria mycotoxins in the grain (mainly TEN and TeA), 19 % of the samples three mycotoxins, and only one sample all four together. In the most of samples the content of Alternaria mycotoxins did not exceed 100 μg/kg, and only TeA content was higher (from 113 to 14963 μg/kg) than others. The significant differences in grain crops by the Alternaria mycotoxins content were revealed: more amounts of AOH, AME, and less amount of TEN were found in oat grain then in barley grain. A high positive significant correlation between the DNA amount of Alternaria section Alternaria fungi and TeA was established that indicates the role of these fungi as the main producers of TeA in the grain.


2018 ◽  
Vol 11 (1) ◽  
pp. 159-174 ◽  
Author(s):  
L. Gambacorta ◽  
D. Magistà ◽  
G. Perrone ◽  
S. Murgolo ◽  
A.F. Logrieco ◽  
...  

Forty-five samples of a landrace of sweet pepper (Capsicum annuum) widely cultivated in Basilicata (Italy) were screened for 17 mycotoxins and potential toxigenic fungal species. Two different LC-MS/MS methods were used for the determination of aflatoxins, ochratoxin A (OTA), Fusarium mycotoxins zearalenone (ZEA), fumonisins (FB1 and FB2), nivalenol (NIV), deoxynivalenol (DON), T-2 and HT-2 toxins and Alternaria mycotoxins altenuene (ALT), alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TTX) and tenuazonic acid (TeA). Frequency of potential toxigenic fungal species occurrence was: 87% Aspergillus Sect. Nigri; 58% Aspergillus Sect. Flavi; 38% Aspergillus Sect. Circumdati; 42% Alternaria spp.; 33% Penicillium spp. and 20% Fusarium spp. Frequency of mycotoxin occurrence and mean of positives were: 51% OTA, 29.5 µg/kg, 5 samples above the EU limit of 20 µg/kg; 31% aflatoxins, 12.8 µg/kg, two samples above the EU limit of 5 µg/kg for aflatoxin B1; 91% ZEA, 1.4 µg/kg; 78% FB2, 7.6 µg/kg; 58% FB1, 22.8 µg/kg; 38% NIV, 39.5 µg/kg; 36% DON, 6.9 µg/kg; 20% T-2 toxin, 5.6 µg/kg and 22% HT-2 toxin, 13.8 µg/kg. For the Alternaria mycotoxins, 100% of samples contained TeA, 4817.9 µg/kg; 93% TTX, 29.7 µg/kg; 56% AOH, 114.4 µg/kg; 33% AME, 13.0 µg/kg and 9% ALT, 61.7 µg/kg. Co-occurrence of mycotoxins in each sample ranged from 2 to 16 mycotoxins (mean 7). No statistical correlation was found between moulds and their mycotoxins occurrence. Within the four groups of peppers collected herein (fresh, dried, grounded and fried) higher percentages of contamination and mycotoxin levels were measured in grounded peppers, whereas much lower values were observed for fried peppers. The high percentages of positive samples and the high levels of some mycotoxins observed in this study confirm the susceptibility of peppers to mycotoxin contamination and claims for an improvement of the conditions used during production and drying process.


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