Examinando por Autor "Prieto, Maria"

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A new lineage of mazaediate fungi in the Eurotiomycetes: Cryptocaliciomycetidae subclass. nov., based on the new species Cryptocalicium blascoi and the revision of the ascoma evolution.
(Springer, 2021) Prieto, Maria; Etayo, Javier; Olariaga, Ibai
The class Eurotiomycetes (Ascomycota, Pezizomycotina) comprises important fungi used for medical, agricultural, industrial and scientific purposes. Eurotiomycetes is a morphologically and ecologically diverse monophyletic group. Within the Eurotiomycetes, different ascoma morphologies are found including cleistothecia and perithecia but also apothecia or stromatic forms. Mazaediate representatives (with a distinct structure in which loose masses of ascospores accumulate to be passively disseminated) have evolved independently several times. Here we describe a new mazaediate species belonging to the Eurotiomycetes. The multigene phylogeny produced (7 gene regions: nuLSU, nuSSU, 5.8S nuITS, mtSSU, RPB1, RPB2 and MCM7) placed the new species in a lineage sister to Eurotiomycetidae. Based on the evolutionary relationships and morphology, a new subclass, a new order, family and genus are described to place the new species: Cryptocalicium blascoi. This calicioid species occurs on the inner side of loose bark strips of Cupressaceae (Cupressus, Juniperus). Morphologically, C. blascoi is characterized by having minute apothecioid stalked ascomata producing mazaedia, clavate bitunicate asci with hemiamyloid reaction, presence of hamathecium and an apothecial external surface with dark violet granules that becomes turquoise green in KOH. The ancestral state reconstruction analyses support a common ancestor with open ascomata for all deep nodes in Eurotiomycetes and the evolution of closed ascomata (cleistothecioid in Eurotiomycetidae and perithecioid in Chaetothyriomycetidae) from apothecioid ancestors. The appropriateness of the description of a new subclass for this fungus is also discussed
Critical predictors of functional, phylogenetic, and taxonomic diversity are geographically structured in lichen epiphytic communities
(Wiley, 2019-04-11) Hurtado, Pilar; Prieto, Maria; Aragón, Gregorio; Escudero, Adrián; Martínez, Isabel
Assessing the response of biological communities to contrasting environmentalconditions is crucial to predict the effects of global change drivers. The influenceof multiple environmental factors may differ depending on the diversity facetconsidered, which emphasizes the need to simultaneously evaluate the functional(FD), phylogenetic (PD) and taxonomic (TD) diversity.2. To examine how these facets of biodiversity respond to environmental changes,we studied lichen epiphytic communities across 47 beech forest fragments fromtwo biogeographic regions. We applied structural equation modelling to relatehabitat fragmentation, climate and habitat quality with FD, PD and TD. We com‐pared the community response to contrasting climatic conditions by analysing in‐dependently Atlantic and Mediterranean communities.3. We found different major drivers of biodiversity patterns across biogeographicregions. Habitat fragmentation performed the highest effect on lichen communi‐ties, with a reduction of FD, PD and TD at both regions. However, the influenceof climate was stronger in the Atlantic region than in the Mediterranean region,where the effect of habitat quality was superior. The effect of the environmentalpredictors over PD and TD was both direct and indirect through the differentcomponents of FD, and their intensity and sign differed across regions. Changesin PD were not related to changes in TD.4. Synthesis. Our results evidenced that the major environmental drivers affect‐ing epiphytic communities were geographically structured. These drivers modi‐fied the diversity of the epiphytic community directly but also indirectly throughchanges in FD, which emerged as a causal but not unique determinant of PD andTD. Our findings also showed the difficulty for inferring TD through PD. Theseresults emphasize the essential role of FD predicting part of the response of lichencommunities to global change drivers but also highlight the importance of con‐sidering multiple biodiversity facets to understand the effects of environmentalchange on community structure.
Phylogeny, evolution and a re-classification of the Lichinomycetes
(Westerdijk Fungal Biodiversity Institute, 2024-12) Prieto, Maria; Wedin, Mats; Schultz, Matthias
The Lichinomycetes is an independent lichenized lineage within the Ascomycota comprising ca. 390 species and 50 genera. Very few studies have dealt with family and genus classification using molecular data and many groups are in need of thorough revision. Thus, we constructed a multilocus phylogeny (mtSSU, RPB2 and mcm7 gene regions) including 190 specimens of Lichinomycetes belonging to 126 species. Ancestral state reconstruction analyses were carried out to trace the evolution of selected characters. The current classification scheme of the Lichinomycetes based on morphological and anatomical characters is in great conflict with the phylogenetic relationships resulting from the present study. The results suggest substantial non-monophyly at the family and genus levels. A revised classification is proposed here and an overview of genera accepted in the Lichinomycetes is given. Ancestral Lichinomycetes are reconstructed as crustose with pycnoascocarps and octosporous asci. We used a combination of characters to delineate groups including the ascoma development and the type of asci. The revised classification includes 11 new genera, five resurrected genera, and 54 new combinations distributed in four families (three emended and one new). Three new species are also described.
Specialization patterns in symbiotic associations: A community perspective over spatial scales
(Wiley, 2023-07-10) Rodríguez‐Arribas, Clara; Martínez, Isabel; Aragón, Gregorio; Zamorano‐Elgueta, Carlos; Cavieres, Lohengrin; Prieto, Maria
Specialization, contextualized in a resource axis of an organism niche, is a core concept in ecology. In biotic interactions, specialization can be determined by the range of interacting partners. Evolutionary and ecological factors, in combination with the surveyed scale (spatial, temporal, biological, and/or taxonomic), influence the conception of specialization. This study aimed to assess the specialization patterns and drivers in the lichen symbiosis, considering the interaction between the principal fungus (mycobiont) and the associated Nostoc (cyanobiont), from a community perspective considering different spatial scales. Thus, we determined Nostoc phylogroup richness and composition of lichen communities in 11 Nothofagus pumilio forests across a wide latitudinal gradient in Chile. To measure specialization, cyanobiont richness, Simpson's and d′ indices were estimated for 37 mycobiont species in these communities. Potential drivers that might shape Nostoc composition and specialization measures along the environmental gradient were analysed. Limitations in lichen distributional ranges due to the availability of their cyanobionts were studied. Turnover patterns of cyanobionts were identified at multiple spatial scales. The results showed that environmental factors shaped the Nostoc composition of these communities, thus limiting cyanobiont availability to establish the symbiotic association. Besides, specialization changed with the spatial scale and with the metric considered. Cyanolichens were more specialized than cephalolichens when considering partner richness and Simpson's index, whereas the d′ index was mostly explained by mycobiont identity. Little evidence of lichen distributional ranges due to the distribution of their cyanobionts was found. Thus, lichens with broad distributional ranges either associated with several cyanobionts or with widely distributed cyanobionts. Comparisons between local and regional scales showed a decreasing degree of specialization at larger scales due to an increase in cyanobiont richness. The results support the context dependency of specialization and how its consideration changes with the metric and the spatial scale considered. Subsequently, we suggest considering the entire community and widening the spatial scale studied as it is crucial to understand factors determining specialization
Specialization: A Multidimensional and Integrative Perspective.
(Ecological Society of America, 2024-07-02) Rodríguez-Arribas, Clara; Prieto, Maria; Aragón, Gregorio; López-Angulo, Jesus; Escudero, Adrian; Martínez, Isabel
Specialization remains as a controversial and ambiguous term in ecology. Although it has been usually measured using a dichotomic and simplified classification of specialists and generalists, its nature is by far more complex. In the context of biotic interactions, assigning these two labels is usually based on the number of interacting partners (one or few vs. many). Here, we provide a more precise, quantitative, and objective interpretation of the specialization phenomenon combining three different dimensions (specificity, preference, and selectivity) that offer complementary information to quantify specialization. Hence, partner richness is a metric associated with the specificity, Simpson's evenness is related to the preference and d′ index to the selectivity of the biotic interactions. Consequently, we propose a 3D specialization space combining these three metrics which allows to identify the degree of biotic specialization fleeing from its simplified historical interpretation. The proposed space was subsequently evaluated in five natural interacting systems (host–parasite, plant–ant, plant–pollinator, plant–seed disperser, and mycobiont–cyanobacteria) using available data comprising 116 networks with quantitative observations. The results indicate the prevalence of a lax specialization, where most organisms tended to show low values in at least one of the metrics. Predominantly, observations showed high values of specificity and low values of preference and selectivity. This relaxed specialization provides advantages of being specialized, without sentencing it when being too tight. The implementation of this framework provides a useful tool that allows to identify specialization in a more objective, integrative, and universal way for future specialization studies.