Size and sequence heterogeneity in the ITS1 of Xylaria hypoxylon isolates

Platas, Gonzalo; Ruibal, Constantino; Collado, Javier

doi:10.1017/s0953756203008815

Cited by 13 publications

(4 citation statements)

References 25 publications

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“…The ITS1-5.8S-ITS2 fragment of the isolates was amplified with the following primers: ITS1F (Gardes & Bruns 1993), ITS4A (Larena et al 1999), ITS5 and ITS2 (White et al 1990), NL1R (reverse of NL1) (O’Donnell 1993), 18S-1 (Platas et al 2004), ITS1-3: 5′-AGTTCAGCGGGTAGTCC-3′ (designed in the laboratory) and 18S-3: 5′-GATGCCCTTAGATGTTCTGGGG-3′ (designed in-house). The specific primers applied for amplification of each isolate are listed in Table 2.…”

Section: Methodsmentioning

confidence: 99%

High diversity and morphological convergence among melanised fungi from rock formations in the Central Mountain System of Spain

Ruibal¹,

Platas²,

Bills³

2008

persoonia

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Melanised fungi were isolated from rock surfaces in the Central Mountain System of Spain. Two hundred sixty six isolates were recovered from four geologically and topographically distinct sites. Microsatellite-primed PCR techniques were used to group isolates into genotypes assumed to represent species. One hundred and sixty three genotypes were characterised from the four sites. Only five genotypes were common to two or more sites. Morphological and molecular data were used to characterise and identify representative strains, but morphology rarely provided a definitive identification due to the scarce differentiation of the fungal structures or the apparent novelty of the isolates. Vegetative states of fungi prevailed in culture and in many cases could not be reliably distinguished without sequence data. Morphological characters that were widespread among the isolates included scarce micronematous conidial states, endoconidia, mycelia with dark olive-green or black hyphae, and mycelia with torulose, isodiametric or moniliform hyphae whose cells develop one or more transverse and/or oblique septa. In many of the strains, mature hyphae disarticulated, suggesting asexual reproduction by a thallic micronematous conidiogenesis or by simple fragmentation. Sequencing of the internal transcribed spacers (ITS1, ITS2) and 5.8S rDNA gene were employed to investigate the phylogenetic affinities of the isolates. According to ITS sequence alignments, the majority of the isolates could be grouped among four main orders of Pezizomycotina: Pleosporales, Dothideales, Capnodiales, and Chaetothyriales. Ubiquitous known soil and epiphytic fungi species were generally absent from the rock surfaces. In part, the mycota of the rock surfaces shared similar elements with melanised fungi from plant surfaces and fungi described from rock formations in Europe and Antarctica. The possibility that some of the fungi were lichen mycobionts or lichen parasites could not be ruled out.

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Section: Methodsmentioning

confidence: 99%

High diversity and morphological convergence among melanised fungi from rock formations in the Central Mountain System of Spain

Ruibal¹,

Platas²,

Bills³

2008

persoonia

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“…The fragment sizes coincided with those reported from strains MF6263 and MF6321. All these strains had 5 degenerate variant repeat motifs repeated in tandem within the ITS1 gene fragment [36]. DNA sequence comparisons showed that the percentage of similarity among the sequence of the ITS region of these isolates varied from 98 to 99%, with strains MF6263 and MUCL 49879 being the most similar.…”

Section: Resultsmentioning

confidence: 99%

“…Genomic nucleic acids were extracted as previously described [20], [36]. The ITS1-5.8S-ITS2 region was amplified using universal primers ITS4 and ITS5 [63].…”

Section: Methodsmentioning

confidence: 99%

Hypoxylon pulicicidum sp. nov. (Ascomycota, Xylariales), a Pantropical Insecticide-Producing Endophyte

et al. 2012

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BackgroundNodulisporic acids (NAs) are indole diterpene fungal metabolites exhibiting potent systemic efficacy against blood-feeding arthropods, e.g., bedbugs, fleas and ticks, via binding to arthropod specific glutamate-gated chloride channels. Intensive medicinal chemistry efforts employing a nodulisporic acid A template have led to the development of N-tert-butyl nodulisporamide as a product candidate for a once monthly treatment of fleas and ticks on companion animals. The source of the NAs is a monophyletic lineage of asexual endophytic fungal strains that is widely distributed in the tropics, tentatively identified as a Nodulisporium species and hypothesized to be the asexual state of a Hypoxylon species.Methods and ResultsInferences from GenBank sequences indicated that multiple researchers have encountered similar Nodulisporium endophytes in tropical plants and in air samples. Ascomata-derived cultures from a wood-inhabiting fungus, from Martinique and closely resembling Hypoxylon investiens, belonged to the same monophyletic clade as the NAs-producing endophytes. The hypothesis that the Martinique Hypoxylon collections were the sexual state of the NAs-producing endophytes was tested by mass spectrometric analysis of NAs, multi-gene phylogenetic analysis, and phenotypic comparisons of the conidial states. We established that the Martinique Hypoxylon strains produced an ample spectrum of NAs and were conspecific with the pantropical Nodulisporium endophytes, yet were distinct from H. investiens. A new species, H. pulicicidum, is proposed to accommodate this widespread organism.Conclusions and SignificanceKnowledge of the life cycle of H. pulicicidum will facilitate an understanding of the role of insecticidal compounds produced by the fungus, the significance of its infections in living plants and how it colonizes dead wood. The case of H. pulicicidum exemplifies how life cycle studies can consolidate disparate observations of a fungal organism, whether from environmental sequences, vegetative mycelia or field specimens, resulting in holistic species concepts critical to the assessment of the dimensions of fungal diversity.

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“…(Feibelman et al 1994) and Xylaria spp. (Platas et al 2004). The short 5.8S rDNA is usually included in ITS analyses because it is located in between the ITS1 and ITS2 regions and does not alone possess enough variable characters for phylogenetic classifications.…”

Section: The Ribosomal Rna Gene Clustermentioning

confidence: 99%

Ecological impacts of Phlebiopsis gigantea biocontrol treatment against Heterobasidion spp. as revealed by fungal community profiling and population analyses

Vainio¹

2008

Diss. For.

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Wood decay fungi belonging to the species complex Heterobasidion annosum sensu lato are among the most common and economically important species causing root rot and stem decay in conifers of the northern temperate regions. New infections by these pathogens can be suppressed by tree stump treatments using chemical or biological control agents. In Finland, the corticiaceous fungus Phlebiopsis gigantea h a s b e e n f o r m u l a t e d i n t o a commercial biocontrol agent called Rotstop (Verdera Ltd.).This thesis addresses the ecological impacts of Rotstop biocontrol treatment on the mycoflora of conifer stumps. Locally, fungal communities within Rotstop-treated and untreated stumps were analyzed using a novel method based on DGGE profiling of small subunit ribosomal DNA fragments amplified directly from wood samples. Population analyses for P. gigantea and H. annosum s.l. were conducted to evaluate possible risks associated with local and/or global distribution of the Rotstop strain.Based on molecular community profiling by DGGE, we detected a few individual wood-inhabiting fungal species (OTUs) that seemed to have suffered or benefited from the Rotstop biocontrol treatment. The DGGE analyses also revealed fungal diversity not retrieved by cultivation and some fungal sequence types untypical for decomposing conifer wood. However, statistical analysis of DGGE community profiles obtained from Rotstoptreated and untreated conifer stumps revealed that the Rotstop treatment had not caused a statistically significant reduction in the species diversity of wood-inhabiting fungi within our experimental forest plots.Locally, ISSR genotyping of cultured P. gigantea strains showed that the Rotstop biocontrol strain was capable of surviving up to six years within treated Norway spruce stumps, while in Scots pine stumps it was sooner replaced by successor fungal species. In addition, the spread of resident P. gigantea strains into Rotstop-treated forest stands seemed effective in preventing the formation of genetically monomorphic populations in the short run. On a global scale, we detected a considerable level of genetic differentiation between the interfertile European and North American populations of P. gigantea. These results strongly suggest that local biocontrol strains should be used in order to prevent global spread of P. gigantea and hybrid formation between geographically isolated populations.The population analysis for H. annosum s.l. revealed a collection of Chinese fungal strains that showed a high degree of laboratory fertility with three different allopatric H. annosum s.l. taxa. However, based on the molecular markers, the Chinese strains could be clearly affiliated with the H. parviporum taxonomical cluster, which thus appears to have a continuous distribution range from Europe through southern Siberia to northern China.

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Size and sequence heterogeneity in the ITS1 of Xylaria hypoxylon isolates

Cited by 13 publications

References 25 publications

High diversity and morphological convergence among melanised fungi from rock formations in the Central Mountain System of Spain

High diversity and morphological convergence among melanised fungi from rock formations in the Central Mountain System of Spain

Hypoxylon pulicicidum sp. nov. (Ascomycota, Xylariales), a Pantropical Insecticide-Producing Endophyte

Ecological impacts of Phlebiopsis gigantea biocontrol treatment against Heterobasidion spp. as revealed by fungal community profiling and population analyses

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