scholarly journals An Old Yellow Enzyme Gene Controls the Branch Point between Aspergillus fumigatus and Claviceps purpurea Ergot Alkaloid Pathways

2010 ◽  
Vol 76 (12) ◽  
pp. 3898-3903 ◽  
Author(s):  
Christine M. Coyle ◽  
Johnathan Z. Cheng ◽  
Sarah E. O'Connor ◽  
Daniel G. Panaccione
Keyword(s):  
Aspergillus Fumigatus ◽  
Ergot Alkaloid ◽  
Ergot Alkaloids ◽  
Aldehyde Group ◽  
Ring Structure ◽  
Ring Closure ◽  
Claviceps Purpurea ◽  
Wild Type ◽  
Old Yellow Enzyme ◽  
Clavicipitaceous Fungi

ABSTRACT Ergot fungi in the genus Claviceps and several related fungal groups in the family Clavicipitaceae produce toxic ergot alkaloids. These fungi produce a variety of ergot alkaloids, including clavines as well as lysergic acid derivatives. Ergot alkaloids are also produced by the distantly related, opportunistic human pathogen Aspergillus fumigatus. However, this fungus produces festuclavine and fumigaclavines A, B, and C, which collectively differ from clavines of clavicipitaceous fungi in saturation of the last assembled of four rings in the ergoline ring structure. The two lineages are hypothesized to share early steps of the ergot alkaloid pathway before diverging at some point after the synthesis of the tricyclic intermediate chanoclavine-I. Disruption of easA, a gene predicted to encode a flavin-dependent oxidoreductase of the old yellow enzyme class, in A. fumigatus led to accumulation of chanoclavine-I and chanoclavine-I-aldehyde. Complementation of the A. fumigatus easA mutant with a wild-type allele from the same fungus restored the wild-type profile of ergot alkaloids. These data demonstrate that the product of A. fumigatus easA is required for incorporation of chanoclavine-I-aldehyde into more-complex ergot alkaloids, presumably by reducing the double bond conjugated to the aldehyde group, thus facilitating ring closure. Augmentation of the A. fumigatus easA mutant with a homologue of easA from Claviceps purpurea resulted in accumulation of ergot alkaloids typical of clavicipitaceous fungi (agroclavine, setoclavine, and its diastereoisomer isosetoclavine). These data indicate that functional differences in the easA-encoded old yellow enzymes of A. fumigatus and C. purpurea result in divergence of their respective ergot alkaloid pathways.

scholarly journals An Ergot Alkaloid Biosynthesis Gene and Clustered Hypothetical Genes from Aspergillus fumigatus

2005 ◽  
Vol 71 (6) ◽  
pp. 3112-3118 ◽  
Author(s):  
Christine M. Coyle ◽  
Daniel G. Panaccione
Keyword(s):  
Aspergillus Fumigatus ◽  
Ergot Alkaloid ◽  
Biological Activities ◽  
Ergot Alkaloids ◽  
Alkaloid Production ◽  
Genetic Origin ◽  
Biosynthesis Gene ◽  
Opportunistic Human Pathogen ◽  
Clavicipitaceous Fungi ◽  
Hypothetical Genes

ABSTRACT The ergot alkaloids are a family of indole-derived mycotoxins with a variety of significant biological activities. Aspergillus fumigatus, a common airborne fungus and opportunistic human pathogen, and several fungi in the relatively distant taxon Clavicipitaceae (clavicipitaceous fungi) produce different sets of ergot alkaloids. The ergot alkaloids of these divergent fungi share a four-member ergoline ring but differ in the number, type, and position of the side chains. Several genes required for ergot alkaloid production are known in the clavicipitaceous fungi, and these genes are clustered in the genome of the ergot fungus Claviceps purpurea. We investigated whether the ergot alkaloids of A. fumigatus have a common biosynthetic and genetic origin with those of the clavicipitaceous fungi. A homolog of dmaW, the gene controlling the determinant step in the ergot alkaloid pathway of clavicipitaceous fungi, was identified in the A. fumigatus genome. Knockout of dmaW eliminated all known ergot alkaloids from A. fumigatus, and complementation of the mutation restored ergot alkaloid production. Clustered with dmaW in the A. fumigatus genome are sequences corresponding to five genes previously proposed to encode steps in the ergot alkaloid pathway of C. purpurea, as well as additional sequences whose deduced protein products are consistent with their involvement in the ergot alkaloid pathway. The corresponding genes have similarities in their nucleotide sequences, but the orientations and positions within the cluster of several of these genes differ. The data indicate that the ergot alkaloid biosynthetic capabilities in A. fumigatus and the clavicipitaceous fungi had a common origin.

scholarly journals Assessment of ergot (Claviceps purpurea) exposure in pregnant and postpartum beef cows

2018 ◽  
Vol 98 (4) ◽  
pp. 688-700 ◽  
Author(s):  
T. Grusie ◽  
V. Cowan ◽  
J. Singh ◽  
J. McKinnon ◽  
B. Blakley
Keyword(s):  
Ergot Alkaloid ◽  
Post Partum ◽  
Ergot Alkaloids ◽  
Maximum Size ◽  
Beef Cows ◽  
Plasma Prolactin ◽  
Claviceps Purpurea ◽  
Ambient Temperatures ◽  
Beef Cow ◽  
The Impact

Cows were fed ration for 9 wk containing 5, 48, 201, and 822 μg kg−1 ergot alkaloids. The objective was to evaluate the impact of ergot consumption in beef cow–calf operations. Ergot alkaloids up to 822 μg kg−1 did not alter the weight of peripartum and postpartum beef cows (P = 0.93) or nursing calves (P = 0.08), rectal temperature (P = 0.16), or plasma prolactin concentrations (P = 0.30) at moderate ambient temperatures. Ergot did not influence the time (>1 ng mL−1; P = 0.79) or the progesterone concentration (P = 0.38) at the time of first postpartum rise or the size of the first (14 ± 0.6 mm; P = 0.40) and second (13 ± 0.5 mm; P = 0.41) follicles to ovulate. The maximum size of the first postpartum corpus luteum (CL) was 4 mm larger in the 822 μg kg−1 ergot group compared with the control (P = 0.03) for the first ovulation post partum, but not for the second (P = 0.11). There was no effect of ergot exposure on the number of days until the appearance of the first (43 ± 4 d; P = 0.95) or second (52 ± 4 d; P = 0.98) CL post partum. Ergot alkaloid concentrations up to 822 μg kg−1 did not affect pregnancy rates (X2 = 0.36). In conclusion, ergot alkaloid exposure for 9 wk to concentrations as high as 822 μg kg−1 did not alter performance in pregnant and postpartum beef cattle at moderate ambient temperatures.

The effects of selected factors on measured ergot alkaloid content in Claviceps purpurea-infected hexaploid and durum wheat

2016 ◽  
Vol 9 (4) ◽  
pp. 555-564 ◽  
Author(s):  
S.A. Tittlemier ◽  
D. Drul ◽  
M. Roscoe ◽  
J.G. Menzies
Keyword(s):  
Durum Wheat ◽  
Host Plant ◽  
Spring Wheat ◽  
Ergot Alkaloid ◽  
Ergot Alkaloids ◽  
Alkaloid Content ◽  
Claviceps Purpurea ◽  
Wheat Line ◽  
Hard Red Spring Wheat ◽  
Plant Line

Four wheat genotypes, including the ergot-susceptible durum ‘AC Avonlea’ and hard red spring wheat ‘AC Cadillac’, as well as the resistant durum wheat line 9260B-173A and the hard red spring wheat line ‘Kenya Farmer’ wereinoculated with different Claviceps purpurea isolates. Honeydew and sclerotia were collected and analysed for 10 ergot alkaloids. Total concentrations of the 10 ergot alkaloids ranged from 16 µg/kg in honeydew to 1,798 mg/kg insclerotia. Ergonovine and ergosine were the predominant alkaloids in honeydew obtained from plants inoculated with various isolates, whereas ergocristine and ergocryptine were the main alkaloids observed in sclerotia. Bothhost plant and C. purpurea isolate were significant factors affecting total ergot alkaloid concentrations in sclerotia. Irrespective of host plant line, all mean total ergot alkaloid concentrations were higher in sclerotia produced from the EI-2 isolate (695-1,010 mg/kg), as compared to EI-4 (255-594 mg/kg). The mass of total ergot alkaloids was alsopositively correlated with the mass of individual sclerotia produced from these two C. purpurea isolates, with the slope of the regression higher for the EI-2 isolate. The total ergot alkaloid concentrations in sclerotia from various plants inoculated with the same C. purpurea isolate differed; however, the resistance of host plant line did notappear to be consistent with ergot alkaloid content in sclerotia. Concentrations of total ergot alkaloids were highestand lowest in sclerotia from the two lines that are both classified as ‘resistant’, suggesting that the mechanism ofresistance for these lines is not restriction on the production of ergot alkaloids in sclerotia.

Proportions of predominant Ergot alkaloids (Claviceps purpurea) detected in Western Canadian grains from 2014 to 2016

2018 ◽  
Vol 11 (2) ◽  
pp. 259-264 ◽  
Author(s):  
T. Grusie ◽  
V. Cowan ◽  
J. Singh ◽  
J. McKinnon ◽  
B. Blakley
Keyword(s):  
Ergot Alkaloid ◽  
Ergot Alkaloids ◽  
Cereal Crops ◽  
Western Canada ◽  
Claviceps Purpurea ◽  
Total Alkaloids ◽  
Relative Composition ◽  
Equivalence Factor ◽  
Total Alkaloid Content ◽  
Toxicological Significance

Ergot alkaloids, produced by the fungus Claviceps purpurea, are contaminants of cereal crops. Depending on various factors, the relative composition of individual ergot alkaloids can differ among samples. The objective was to determine if the percentage of individual ergot alkaloids were similar across different cereal grains (barley n=39, rye n=7, triticale n=9, wheat n=94) collected in Western Canada over different years. Ergocristine was the predominant alkaloid accounting for half of the total alkaloids in all grain types. This study documented that barley, rye, triticale and wheat collected across Western Canada had similar percentages of ergocornine (6±1%, P=0.201), ergocristine (48±2%, P=0.939), ergocryptine (17±2%, P=0.302) and ergosine (5±0.5%, P=0.239). There were differences between grain types for ergometrine (P=0.027) and ergotamine (P=0.011), which ranged between 6 to 13% and 11 to 24%, respectively, of the total alkaloid content in different cereals. Both barley and wheat alkaloid percentages were similar between 2015 and 2016; ergocornine (7±1%, P=0.969), ergocristine (47±2%, P=0.680), ergocryptine (18±2%, P=0.572), ergometrine (8±1%, P=0.080), ergosine (15±1%, P=0.119) and ergotamine (P=0.189). The ergocornine percentage was higher in wheat (P=0.017) as compared to barley for 2015/2016 samples. Ergometrine was higher in barley (P=0.002) as compared to wheat for 2015/2016 samples. While two of the alkaloid proportions varied statistically, overall proportions of the six ergot alkaloids were comparable among the four grain types collected across Western Canada. If proportions of ergot alkaloids are similar across a region, then it may be deemed acceptable to recommend a maximum total ergot alkaloid concentration for that region. However, areas that exhibit variation among the ergot alkaloid proportions, individual ergot alkaloid guidelines based on a toxic equivalence factor, may be more appropriate. In contrast, since major differences were not seen between years or grain type, from a producer perspective there may be limited biological/toxicological significance for individual alkaloid guidelines.

Correlation and variability between weighing, counting and analytical methods to determine ergot (Claviceps purpurea) contamination of grain

2017 ◽  
Vol 10 (3) ◽  
pp. 209-218 ◽  
Author(s):  
T. Grusie ◽  
V. Cowan ◽  
J. Singh ◽  
J. McKinnon ◽  
B. Blakley
Keyword(s):  
Particle Size ◽  
Ergot Alkaloid ◽  
Total Alkaloid ◽  
High Performance ◽  
Ergot Alkaloids ◽  
Sample Volume ◽  
Small Sample ◽  
Claviceps Purpurea ◽  
Liquid Chromatography Tandem Mass ◽  
The Impact

Ergot alkaloid mycotoxins produced by the fungus Claviceps purpurea, are contaminants of cereal crops and grasses. The objectives of this study were to determine the correlation between number of ergot sclerotia and weight compared to the total ergot alkaloid concentration, to evaluate the effect of grinding process (i.e. particle size (PS)) on ergot alkaloid analysis using high performance liquid chromatography – tandem mass spectrometry, and to determine the impact of sample volume on analytical variability. This study demonstrated that correlations exist between both ergot sclerotia count (R2=0.7242, P<0.001) and ergot sclerotia weight (R2=0.9618, P<0.001) compared to the total alkaloid concentration of 6 ergot alkaloids. However, at alkaloid ergot concentrations below 350 µg/kg grain, ergot sclerotia count (R2=0.0002, P=0.956) and ergot sclerotia weight (R2=0.0064, P=0.769) were not correlated to the total alkaloid concentration. A lower variability (P=0.041), defined by coefficient of variation (CV), was observed using a commercial UDY cyclone sample mill (PS=192 µm, CV=9 µg/kg) as compared to a household coffee grinder (PS=516 µm, CV=66 µg/kg). Total amount and concentration of individual ergot alkaloids varied (P<0.05) among sclerotia of similar weight. For the analytical method, CV was numerically reduced as sample volume increased (97% CV for 75 ml to 64% CV for 1000 ml; mean of all concentrations) but increased as sample concentration declined (17% CV for 81,678 µg/kg to 284% for 35 µg/kg; mean of all sample volumes). This implies that analysis of small sample volumes at low ergot alkaloid concentrations may result in highly variable and potentially misleading results. In conclusion, number of ergot sclerotia and weight are unreliable indicators of alkaloid content at ergot concentrations below 350 µg/kg and particle size influences the variability. An analytical approach with fine grinding (mean PS<200 µm, 85% particles <400 µm) of a large sample should be used to assess low-level ergot contamination.

SOME ASPECTS OF PHOSPHATE METABOLISM OF CLAVICEPS PURPUREA (FR.) TUL.: II. RELATIONSHIP BETWEEN NUCLEIC ACIDS SYNTHESIS AND ERGOT ALKALOID PRODUCTION

1961 ◽  
Vol 7 (6) ◽  
pp. 883-888 ◽  
Author(s):  
C. de Waart
Keyword(s):  
Nucleic Acid ◽  
Ergot Alkaloid ◽  
Ribonucleic Acid ◽  
Ergot Alkaloids ◽  
Acid Synthesis ◽  
Claviceps Purpurea ◽  
Phosphate Metabolism ◽  
Alkaloid Production ◽  
Phosphorus Containing ◽  
Insoluble Phosphate

A study was made of the distribution of the phosphorus-containing compounds in the phosphate pool of stationary cultures of Claviceps purpurea (Fr.) Tul. Exogenous KH2PO4 was mainly converted to ribonucleic acid. Conditions favorable to increased nucleic acid synthesis increased the yield of ergot alkaloids. The proportion of nucleic acid and acid-insoluble phosphate fraction appeared to be an important factor influencing the ergot alkaloid production.

Ergot alkaloid biosynthesis by isolates of Balansia epichloë and B. henningsiana

1981 ◽  
Vol 59 (12) ◽  
pp. 2534-2538 ◽  
Author(s):  
Charles W. Bacon ◽  
James K. Porter ◽  
Joe D. Robbins
Keyword(s):  
Ergot Alkaloid ◽  
Sampling Site ◽  
Total Yield ◽  
Ergot Alkaloids ◽  
Chemical Species ◽  
Alkaloid Biosynthesis ◽  
Andropogon Virginicus ◽  
Clavicipitaceous Fungi

Two endophytic clavicipitaceous fungi, Balansia epichloë and B. henningsiana, were isolated from several grasses, cultured on laboratory media, and assessed for their ability to produce the major ergot alkaloids agroclavine, chanoclavine (I), ergonovine, and ergonovinine. Data indicated that the ability of these two species of fungi to biosynthesize ergot alkaloids was host related. All isolates of B. epichloë from smut-grass (Sporobolus poiretii) and 59% of the isolates of B. henningsiana from broom-sedge (Andropogon virginicus) produced the major alkaloids in culture. All isolates of B. epichloë from Eragrostis secundiflora and E. hirsuta, and all isolates of B. henningsiana from Panicum tenerum failed to produce alkaloids. The total yield and chemical species of individual alkaloids varied among isolates from a sampling site.

scholarly journals Ergot Alkaloid Contents in Hybrid Rye are Reduced by Breeding

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 526
Author(s):  
Thomas Miedaner ◽  
Anna Kodisch ◽  
Armin Raditschnig ◽  
Jakob Eifler
Keyword(s):  
Ergot Alkaloid ◽  
Value Chain ◽  
Ergot Alkaloids ◽  
General Combining Ability ◽  
Phytopathogenic Fungus ◽  
Claviceps Purpurea ◽  
Lower Content ◽  
Wide Range ◽  
Hybrid Rye ◽  
Alkaloid Contents

Contamination by ergot caused by the phytopathogenic fungus Claviceps purpurea is a constant threat to the whole rye value chain. Ergot alkaloids (EA) produced within the fungal sclerotia are toxic for humans and animals and are subjected to strict regulations in human food. Our main objective was to analyze whether less susceptible rye cultivars with a lower content of sclerotia also contain fewer ergot alkaloids (EA). We analyzed 15 factorial single crosses in multi-environmental trials with artificial inoculation for their ergot severity, the content of twelve EAs by HPLC, and the total ergot content by ELISA. The genotypes displayed a wide range of pollen shedding from fully sterile to fully fertile, of ergot severity expressed as percentage of sclerotia relative to the harvest (0.22–11.47%), and of EA contents when analyzed by HPLC (0.57–45.27 mg/kg. Entry-mean heritabilities were high throughout (0.87–0.98). The factorial analysis yielded a preponderance of male general combining ability (GCA) variances, the estimates for the females were smaller, although significant. EA contents measured by ELISA were, on average, seven times larger. The correlation between ergot severity and EA contents determined by HPLC was r = 0.98 (p ≤ 0.01) and only somewhat lower when analyzed by ELISA. In conclusion, less ergot prone rye genotypes also support lower EA contents.

scholarly journals Links Between Genetic Groups, Host Specificity, and Ergot-Alkaloid Profiles within Claviceps purpurea (Fr.) Tul. on Slovenian Grasses

Plant Disease ◽  
2018 ◽  
Vol 102 (7) ◽  
pp. 1334-1340
Author(s):  
Matevž Likar ◽  
Marjana Grandič ◽  
Breda Jakovac Strajn ◽  
Katarina Kos ◽  
Franci Aco Celar
Keyword(s):  
Host Specificity ◽  
Ribosomal Dna ◽  
Ergot Alkaloid ◽  
Animal Feed ◽  
Genetic Relationships ◽  
Ergot Alkaloids ◽  
Claviceps Purpurea ◽  
Alkaloid Production ◽  
Alkaloid Composition ◽  
Genetic Groups

In the present study, the genetic relationships and ergot-alkaloid production of the fungus Claviceps purpurea on grasses were investigated, to determine any associations between grass host specificity, ergot-alkaloid production, and geographic origin. C. purpurea sclerotia were obtained from wild and cultivated grasses along a 300-km climatic gradient, from sub-Mediterranean to continental climates. Twenty-one infected grass samples provided 39 sclerotia for analysis of the ergot alkaloids ergometrine, ergosine, ergotamine, ergocornine, ergocryptine, and ergocristine, and their “-inine” epimers, using liquid chromatography–tandem mass spectrometry. C. purpurea ribosomal DNA underwent molecular classification to determine any grass host or geographic specificity of ergot-alkaloid composition for the different operational taxonomic units. Molecular analysis of sclerotia ribosomal DNA showed three genetic groups, with some associations with specific grass host taxonomic groups. The ergot-alkaloid composition data were in agreement with the data obtained by molecular methods. The most frequent ergot-alkaloid epimers were ergocristine, and ergosine. The total ergot-alkaloid concentrations in sclerotia varied from 59 to 4,200 mg kg–1, which corresponds to 0.059 to 4.2 mg kg–1 in animal feed (assuming ergot alkaloids at 1,000 mg kg–1 sclerotia). Therefore, grasses can be associated with significant levels of ergot alkaloids. In addition, the ergot-alkaloid compositions of C. purpurea sclerotia can be different for infections with different C. purpurea genetic groups, because these show different ergot-alkaloid compositions.

Sign in / Sign up

Export Citation Format

Share Document