Microscopic Details and Fluorescent Characteristics of the Stromata of Xylaria polymorpha (Pers.) Grev. (Xylariales, Ascomycota)

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AudienciaPúblico en generales_ES
CoberturaMéxicoes_ES
Fecha de ingreso2026-09-15T00:31:41Z
Fecha de publicación2026-07-01
ResumenThe genus Xylaria Hill ex Schrank 1786 presents perithecia in carbonaceous, dark stromata, with great morphological variability; these may be cylindrical, stipitate, peltate or pulvinate; with globose to elongated immersed perithecia, possessing umbilicate or papillate ostioles; asci uniseriate, cylindrical, with an apical pore, almost rectangular, with amyloid reaction [1]. Several chemical groups of taxonomic and industrial importance have been described in the genus Xylaria. Many of these molecules contain unsaturated chains that confer fluorescent properties, where electrons are excited by ultraviolet light, emitting yellow, blue, or green light. Chemical compounds reported in the genus include sesquiterpenoids, diterpenoids, diterpenoid glycosides, triterpenoid glycosides, steroids, aromatic compounds, pyrone derivatives, and polyketides. These compounds possess important biological properties, including antimicrobial activity, antimalarial activity, cytotoxic activity, anti-obesity effects, acetylcholinesterase inhibition, L-type calcium channel blocking activity and anti-HSV-1 activity [2]. Longitudinal and transverse sections of X. polymorpha specimens were prepared. The obtained sections were placed on cylindrical aluminum specimen holders. A square of double-sided copper tape was placed on these cylinders, onto which the samples were mounted for observation under a scanning electron microscope. Samples were coated with a thin gold film by sputter coating to ensure electron conductivity and proper observation of fungal surface structures. This process was carried out under vacuum for 5 minutes using a sputter coater, and samples were observed with a scanning electron microscope. For optical microscopy analysis, a VELAB model VE-B1 microscope was used. Longitudinal sections of stromata were mounted in 70% alcohol and 10% potassium hydroxide (KOH) and examined to analyze cellular types present in the perithecium. For fluorescence observation, thick stromatal sections were prepared and observed under an optical microscope using incident ultraviolet light at 395 nm. Structures exhibiting fluorescence under these conditions were identified, including Sordariomycetes, Xylariales, Xylariaceae, and Xylaria polymorpha (Pers.) Grev. 1824. The species description can be consulted in [3]. This species is morphologically similar to Xylaria abovata (Berk.) Berk. It is characterized by globose to ovoid stromata measuring 13.20 mm in diameter, brown to reddish-brown in color, almost black, on a thin stipe less than 1-2 mm in diameter; the stromatal surface is rough, with perithecia immersed in the stroma, punctate ostioles and very hard texture. Asci are long-stipitate, measuring 165–190 x 8–10 μm, considering only the spore-bearing portion, with an amyloid apical pore measuring 4–5 x 4 μm. Spores measure (20-) 21-28 x 7-8 μm, with a spiral germ line, olive to dark brown in color. Paraphyses are filiform and hyaline. This species belongs to the Xylaria polymorpha complex, from which it is distinguished by having a thin stipe and slightly reticulated stromatal surface, giving it a rough appearance [4]. Another morphologically similar species is Xylaria grammica (Mont.) Fr. Characterized by claviform stromata, sometimes with acute apices, with a gray-whitish surface initially and later dark brown, leaving a pattern of longitudinal whitish cracks, immersed ostioles, and spores measuring 11–15 x 4.5-5.5 μm. These are characteristic features of this species according to Pérez-Silva [5], and Van der Gucht [6]. The morphological characteristics observed under optical and electron microscopy correspond morphologically to the cited species [3,7,8]. New ultrastructural data are provided regarding the ostiole, which is internal, central, containing ascospores, entire, with internal projections, and incomplete periphyses. The perithecia are ovoid, irregular, with thick walls that don’t collapse, and present a reticulated external surface. A layer of cells surrounding each perithecium can be distinguished, marking the separation from the stroma. This layer is characterized by having small cells with thin, smooth walls, separated from each other by a melanin matrix, which provides the dark coloration. The stroma is composed of round cells with globular texture and thin walls. Regarding the brightness observed under ultraviolet light, the presence of a stromatal surface with yellow fluorescence is observed, which does not cover the entire structure. In contrast, the internal stromatal cells do not exhibit any fluorescent properties, whereas the cells of the fertile region show strong blue fluorescence, both in asci and paraphyses. The ascospores do not exhibit this property. This is the first time that this property has been reported in the genus Xylaria. The metabolites present in these structures are responsible for the fluorescence, among which terpenoids, xanthones, coumarins, isocoumarins, chromans, napthalenes, and anthraquinone derivates stand out [2]. Xylaria is one of the most numerous and diverse genera within the phylum Ascomycota, with predominantly tropical distribution. The variability in stromatal morphology and the absence of type specimens have generated extensive synonymy. Secondary metabolites of Xylaria exhibit biological activities, including antimicrobial and cytotoxic effects. The fluorescence of these compounds suggest additional potential as chemotaxonomic markers, including aromatic and phenolic compounds such as xanthones, coumarins, isocoumarins, chromans, naphthalenes, and anthraquinone derivates. Scanning electron microscopy of Xylaria polymorpha (Pers.) Grev. A, Surface view of the stroma with mature perithecia. B, Detail of a mature perithecium in the stroma. C, Detail of the ostiole. D, Close-up of the perithecial surface and the junction zone between the perithecium and the stroma. Scanning electron microscopy of Xylaria polimorpha (Pers.) Grev. A, View of the stroma without perithecium. B, Detail of the cells at the perithecial periphery. C, Detail of stomatal cells. Xylaria polymorpha (Pers.) Grev. A, Transverse section of the stroma. B–D, Details of the perithecium observed under optical microscopy. Fluorescence at 395 nm of Xylaria polymorpha (Pers.) Grev. A, Yellow fluorescence on the stromatal surface. B–D, Blue fluorescence in the hymenium of the perithecia.es_ES
Doihttps://doi.org/10.1093/mam/ozag053.488es_ES
URIhttps://riuat.uat.edu.mx/handle/123456789/3364
Idiomaenes_ES
EditorialOxford University Presses_ES
RelaciónMicroscopy and Microanalysises_ES
URL relacionadohttps://doi.org/10.1093/mam/ozag053.488es_ES
DerechosAcceso restringido / Suscripción (Metadatos de producción científica)es_ES
Licenciahttp://purl.org/coar/access_right/c_16eces_ES
FuenteMicroscopy and Microanalysis
Palabra claveFluorescencees_ES
Palabra claveFluorescence microscopees_ES
Palabra claveFluorescent labellinges_ES
Palabra claveFluorescent lightes_ES
ClasificaciónPlant Pathogens and Fungal Diseaseses_ES
TítuloMicroscopic Details and Fluorescent Characteristics of the Stromata of Xylaria polymorpha (Pers.) Grev. (Xylariales, Ascomycota)es_ES
TipoArtículoes_ES
ArbitradoHa sido Arbitradoes_ES
AutorMartínez-Pineda, Michelle
AutorRucabado, Viridiana
AutorLópez-Naranjo, Jessica L
AutorHernández, Javier
AutorMontenegro, Mabel M.
AutorPastén-Borja, Ricardo Pérez
AutorParedes-Sánchez, Francisco Alejandro
AutorALVAREZ-CORTÉS, PEDRO MIGUEL
AutorMartínez-Pineda, Michellees_ES
AutorRucabado, Viridianaes_ES
AutorLópez-Naranjo, Jessica Les_ES
AutorHernández, Javieres_ES
AutorMontenegro, Mabel M.es_ES
AutorPastén-Borja, Ricardo Pérezes_ES
AutorParedes-Sánchez, Francisco Alejandroes_ES
AutorALVAREZ-CORTÉS, PEDRO MIGUELes_ES
InstituciónUniversidad Autónoma de Tamaulipas
InstituciónUniversidad Autónoma de Tamaulipases_ES
NúmeroSupplement_1es_ES
URL relacionadahttps://doi.org/10.1093/mam/ozag053.488
Tipo de artículoIndexado
Tipo de artículoIndexadoes_ES
Volumen32es_ES

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