7 results on '"Laraba, Imane"'
Search Results
2. Fusarium abutilonis and F. guadeloupense , two novel species in the Fusarium buharicum clade supported by multilocus molecular phylogenetic analyses.
- Author
-
O'Donnell K, Gräfenhan T, Laraba I, Busman M, Proctor RH, Kim HS, Wiederhold NP, Geiser DM, and Seifert KA
- Subjects
- Humans, Phylogeny, Plant Diseases, Soil, Texas, Fusarium, Mycotoxins metabolism
- Abstract
This study was conducted to elucidate evolutionary relationships and species diversity within the Fusarium buharicum species complex (FBSC). We also evaluate the potential of these species to produce mycotoxins and other bioactive secondary metabolites. Maximum likelihood and maximum parsimony analyses of sequences from portions of four marker loci (ITS rDNA, TEF1, RPB1 , and RPB2 ) and the combined 4495 bp data set support recognition of seven genealogically exclusive species within the FBSC. Two of the three newly discovered species are formally described as F. abutilonis and F. guadeloupense based on concordance of gene genealogies and morphological data. Fusarium abutilonis induces leaf, stem, and root lesions on several weedy Malvaceae ( Abution theophrasti, Anoda cristata, Sida spinosa ) and a fabaceous host ( Senna obtusifolia ) in North America and also was recovered from soil in New Caledonia. Fusarium abutilonis , together with its unnamed sister, Fusarium sp. ex common marsh mallow ( Hibiscus moscheutos ) from Washington state, and F. buharicum pathogenic to cotton and kenaf in Russia and Iran, respectively, were strongly supported as a clade of malvaceous pathogens. The four other species of the FBSC are not known to be phytopathogenic; however, F. guadeloupense was isolated from human blood in Texas and soil in Guadeloupe. The former isolate is unique because it represents the only known case of a fusarial infection disseminated hematogenously by a species lacking microconidia and the only documented fusariosis caused by a member of the FBSC. Whole genome sequence data and extracts of cracked maize kernel cultures were analyzed to assess the potential of FBSC isolates to produce mycotoxins, pigments, and phytohormones.
- Published
- 2022
- Full Text
- View/download PDF
3. An endophyte of Macrochloa tenacissima (esparto or needle grass) from Tunisia is a novel species in the Fusarium redolens species complex.
- Author
-
Gargouri S, Balmas V, Burgess L, Paulitz T, Laraba I, Kim HS, Proctor RH, Busman M, Felker FC, Murray T, and O'Donnell K
- Subjects
- DNA, Fungal genetics, DNA, Ribosomal genetics, Endophytes chemistry, Endophytes classification, Endophytes cytology, Endophytes physiology, Fusarium chemistry, Fusarium cytology, Genes, Fungal genetics, Genes, Mating Type, Fungal genetics, Genome, Fungal genetics, Phylogeny, Plant Roots microbiology, Secondary Metabolism, Sequence Analysis, DNA, Species Specificity, Tunisia, Fusarium classification, Fusarium physiology, Poaceae microbiology
- Abstract
Here, we report on the morphological, molecular, and chemical characterization of a novel Fusarium species recovered from the roots and rhizosphere of Macrochloa tenacissima (halfa, esparto, or needle grass) in central Tunisia. Formally described here as F. spartum , this species is a member of the Fusarium redolens species complex but differs from the other two species within the complex, F. redolens and F. hostae , by its endophytic association with M. tenacissima and its genealogical exclusivity based on multilocus phylogenetic analyses. To assess their sexual reproductive mode, a polymerase chain reaction (PCR) assay was designed and used to screen the three strains of F. spartum , 51 of F. redolens , and 14 of F. hostae for mating type ( MAT ) idiomorph. Genetic architecture of the MAT locus in the former two species suggests that if they reproduce sexually, it is via obligate outcrossing. By comparison, results of the PCR assay indicated that 13/14 of the F. hostae strains possessed MAT1-1 and MAT1-2 idiomorphs and thus might be self-fertile or homothallic. However, when the F. hostae strains were selfed, 11 failed to produce perithecia and one only produced several small abortive perithecia. Cirrhi with ascospores, however, were only produced by 8/28 and 4/84 of the variable size perithecia, respectively, of F. hostae NRRL 29888 and 29890. The potential for the three F. redolens clade species to produce mycotoxins, pigments, and phytohormones was assessed by screening whole genome sequence data and by analyzing extracts on cracked maize kernel cultures via liquid chromatography-mass spectrometry.
- Published
- 2020
- Full Text
- View/download PDF
4. Fusarium xyrophilum , sp. nov., a member of the Fusarium fujikuroi species complex recovered from pseudoflowers on yellow-eyed grass ( Xyris spp.) from Guyana.
- Author
-
Laraba I, Kim HS, Proctor RH, Busman M, O'Donnell K, Felker FC, Aime MC, Koch RA, and Wurdack KJ
- Subjects
- DNA, Fungal genetics, Fungal Proteins genetics, Fusarium cytology, Fusarium genetics, Genes, Mating Type, Fungal genetics, Genome, Fungal genetics, Guyana, Phylogeny, Sequence Analysis, DNA, Spores, Fungal classification, Spores, Fungal cytology, Spores, Fungal genetics, Biological Mimicry, Flowers, Fusarium classification, Poaceae microbiology
- Abstract
We report on the discovery and characterization of a novel Fusarium species that produced yellow-orange pseudoflowers on Xyris spp. (yellow-eyed grass; Xyridaceae) growing in the savannas of the Pakaraima Mountains of western Guyana. The petaloid fungal structures produced on infected plants mimic host flowers in gross morphology. Molecular phylogenetic analyses of full-length RPB1 (RNA polymerase largest subunit), RPB2 (RNA polymerase second largest subunit), and TEF1 (elongation factor 1-α) DNA sequences mined from genome sequences resolved the fungus, described herein as F. xyrophilum , sp. nov., as sister to F. pseudocircinatum within the African clade of the F. fujikuroi species complex. Results of a polymerase chain reaction (PCR) assay for mating type idiomorph revealed that single-conidial isolates of F. xyrophilum had only one of the MAT idiomorphs ( MAT1-1 or MAT1-2 ), which suggests that the fungus may have a heterothallic sexual reproductive mode. BLASTn searches of whole-genome sequence of three strains of F. xyrophilum indicated that it has the genetic potential to produce secondary metabolites, including phytohormones, pigments, and mycotoxins. However, a polyketide-derived pigment, 8- O -methylbostrycoidin, was the only metabolite detected in cracked maize kernel cultures. When grown on carnation leaf agar, F. xyrophilum is phenotypically distinct from other described Fusarium species in that it produces aseptate microconidia on erect indeterminate synnemata that are up to 2 mm tall and it does not produce multiseptate macroconidia.
- Published
- 2020
- Full Text
- View/download PDF
5. Molecular systematics of two sister clades, the Fusarium concolor and F. babinda species complexes, and the discovery of a novel microcycle macroconidium-producing species from South Africa.
- Author
-
Jacobs-Venter A, Laraba I, Geiser DM, Busman M, Vaughan MM, Proctor RH, McCormick SP, and O'Donnell K
- Subjects
- Animals, Cattle microbiology, Endophytes classification, Fusarium pathogenicity, Genetic Variation, Genome, Fungal, Multigene Family, Multilocus Sequence Typing, Mycological Typing Techniques, Mycotoxins genetics, Sequence Analysis, DNA, South Africa, Spores, Fungal physiology, Whole Genome Sequencing, Fusarium classification, Phylogeny, Poaceae microbiology, Soil Microbiology
- Abstract
Multilocus DNA sequence data were used to investigate species identity and diversity in two sister clades, the Fusarium concolor (FCOSC) and F. babinda species complexes. Of the 109 isolates analyzed, only 4 were received correctly identified to species and these included 1/46 F. concolor, 1/31 F. babinda, and 2/3 F. anguioides. The majority of the F. concolor and F. babinda isolates were received as F. polyphialidicum, which is a heterotypic synonym of the former species. Previously documented from South America, Africa, Europe, and Australia, our data show that F. concolor is also present in North America. The present study expands the known distribution of F. babinda in Australia to Asia, Europe, and North America. The molecular phylogenetic results support the recognition of a novel Fusarium species within the FCOSC, which is described and illustrated here as F. austroafricanum, sp. nov. It was isolated as an endophyte of kikuyu grass associated with a putative mycotoxicosis of cattle and from plant debris in soil in South Africa. Fusarium austroafricanum is most similar morphologically to F. concolor and F. babinda but differs from the latter two species in producing (i) much longer macroconidia in which the apical cell is blunt to slightly papillate and the basal cell is only slightly notched and (ii) macroconidia via microcycle conidiation on water agar. BLASTn searches of the whole genome sequence of F. austroafricanum NRRL 53441 were conducted to predict mycotoxin potential, using genes known to be essential for the synthesis of several mycotoxins and biologically active metabolites. Based on the presence of intact gene clusters that confer the ability to synthesize mycotoxins and pigments, we analyzed cracked corn kernel cultures of F. austroafricanum via liquid chromatography-mass spectrometry (LC-MS) but failed to detect these metabolites in vitro.
- Published
- 2018
- Full Text
- View/download PDF
6. Fusarium subtropicale, sp. nov., a novel nivalenol mycotoxin-producing species isolated from barley (Hordeum vulgare) in Brazil and sister to F. praegraminearum.
- Author
-
Pereira CB, Ward TJ, Tessmann DJ, Del Ponte EM, Laraba I, Vaughan MM, McCormick SP, Busman M, Kelly A, Proctor RH, and O'Donnell K
- Subjects
- Brazil, Fusarium genetics, Fusarium metabolism, Genes, Mating Type, Fungal, Genotype, Genotyping Techniques methods, Microscopy, Microscopy, Electron, Scanning, Multilocus Sequence Typing methods, Mycological Typing Techniques methods, Peptide Elongation Factor 1 genetics, Plant Diseases microbiology, Spores, Fungal cytology, Triticum microbiology, Fusarium classification, Fusarium isolation & purification, Hordeum microbiology, Mycotoxins metabolism, Phylogeny, Trichothecenes metabolism
- Abstract
Surveys were conducted in commercial wheat and barley fields in the south central production regions of state of Paraná, Brazil, from 2011 to 2015. Spikes displaying visible Fusarium head blight symptoms were collected and the pathogen isolated from the tissues. The 754 Fusarium isolates recovered were identified by a high-throughput multilocus genotyping assay (MLGT) designed to identify trichothecene toxin-producing fusaria (i.e., formerly B-clade, but referred to here as F. sambucinum species complex lineage 1 [FSAMSC-1]) together with sequencing a portion of the translation elongation factor 1-α (TEF1) gene. One strain was discovered that appeared to be closely related to but phylogenetically distinct from F. praegraminearum based on the relatively low 97.7% TEF1 identity and positive genotype obtained with one of the two F. praegraminearum species-specific MLGT probes. Molecular phylogenetic analyses of a 10-gene data set resolved this novel FSAMSC-1 species and F. praegraminearum as sisters. Formally described herein as F. subtropicale, it is phenotypically distinct from the 22 other FSAMSC-1 species in that it produces mostly 1-3-septate macroconidia. Whole-genome sequence data were used to predict its potential to produce mycotoxins. Chemical analyses confirmed that F. subtropicale could produce the mycotoxins 4,15-diacetylnivalenol, butenolide, culmorin, and fusarin C in vitro, and the pathogenicity experiment revealed that F. subtropicale could infect but not spread in susceptible hard red spring wheat cultivar "Norm."
- Published
- 2018
- Full Text
- View/download PDF
7. Fusarium algeriense, sp. nov., a novel toxigenic crown rot pathogen of durum wheat from Algeria is nested in the Fusarium burgessii species complex.
- Author
-
Laraba I, Keddad A, Boureghda H, Abdallah N, Vaughan MM, Proctor RH, Busman M, and O'Donnell K
- Subjects
- Algeria, Chromatography, Liquid, Fusarium genetics, Fusarium growth & development, Genes, Mating Type, Fungal, Mass Spectrometry, Metabolic Networks and Pathways genetics, Microscopy, Multilocus Sequence Typing, Mycelium growth & development, Mycological Typing Techniques, Mycotoxins analysis, Phylogeny, Sequence Analysis, DNA, Spores, Fungal cytology, Spores, Fungal growth & development, Whole Genome Sequencing, Fusarium classification, Fusarium isolation & purification, Plant Diseases microbiology, Triticum microbiology
- Abstract
A novel crown rot pathogen of wheat discovered during pathogen surveys in Algeria in 2014 and 2015 is formally described as Fusarium algeriense. Multilocus molecular phylogenetic data resolved the eight isolates of this pathogen as a genealogically exclusive species lineage in the F. burgessii species complex. The previously described species of this complex, F. burgessii and F. beomiforme, produce abundant chlamydospores in culture, and their optimal temperature for growth is 30 C. In comparison, F. algeriense did not produce chlamydospores under the conditions tested and its optimal temperature for growth is 25 C. Furthermore, F. algeriense differs from F. burgessii because it does not produce polyphialides and F. beomiforme, because it does not produce globose-to-napiform conidia in the aerial mycelium. Isolates of F. algeriense induced moderate crown rot on the susceptible spring wheat cultivar Norm in a temperature-controlled incubator. Fusarium burgessii and F. beomiforme, in contrast, only induced mild symptoms of this disease. BLASTn searches of the whole-genome sequence of F. algeriense strains NRRL 66647 and 66648, using homologs of genes that are responsible for synthesis of toxic secondary metabolites, indicated that they have the potential to produce several polyketide and non-ribosomal peptide-derived mycotoxins. However, moniliformin and 2-AOD-ol (2-amino-14,16-dimethyloctadecan-3-ol) were the only mycotoxins detected by liquid chromatography-mass spectrometry (LC-MS) analyses of strains cultivated in vitro on a solid medium. A polymerase chain reaction (PCR) assay for MAT idiomorph revealed that MAT1-1 and MAT1-2 strains of F. algeriense were present in Algeria, which suggests this pathogen might possess a heterothallic sexual reproductive mode.
- Published
- 2017
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.