Four lichen species new to Spain

Se presentan cuatro nuevas citas de líquenes de España, concretamente Aspicilia ruceniuro, Lecanora stenotropa, Vezdaea leprosa y Xanthoparmelia plitii. Las especies probablemente no son raras pero habían sido obviadas, bien por ser inconspicuas bien por ser similares morfológicamente a otras especies.Four species of Lichens are reported as new to Spain, namely Aspicilia moenium, Lecanora stenotropa, Vezdaea leprosa aud Xanthoparmelia plitii. The species are probably not rare, but overlooked, since they are either inconspicuous or morphologically similar to other [email protected]

Sobre las comunidades terrícolas de líquenes vagantes (Sphaerothallio-xanthoparmelion vagantis al. nova)

Se propone una nueva alianza Sphaerothaiio-Xanthoparmelion vagantis, de líquenes errantes de lugares fisiológicamente áridos (termo o crioáridos), por continentalidad o desertización higrotérmica fuertemente venteados y eútrofos. En el seno de esta alianza describimos una nueva asociación Sphaerothaiietum fruticuloso-foliaceae que se desarrolla, en España, en el piso de vegetacióji ibérico de paramera en los claros de las comunidades de tomillar-pradera de Festuco-Po ion li~giílatae, entre 1.200-1.400 m. de altitud y que, sin duda, supera el ámbito de la Región Mediterránea, encontrando tal vez un óptimo en la Irano-Turánica. Datos bibliográficos nos hacen deducir su presencia en las montañas de Astrakan, y Tauria (Rusia). Se incluye también en la alianza la asociación Parmelietum vagantis (Keller 1938) Klement 1955 enmendándola profundamente. Discutimos en el trabajo las comunidades afines a las descritas, en base a conceptos florísticos y ecológicos (Dzfrloschistion terrestris Klement 1955 y Parmelietum vagantis (Keller 1938) Klement 1955

Diversidad liquénica asociada a fenómenos post-incendio en los alcornocales valenciano-castellonenses.

[email protected] [email protected] [email protected] estudia la colonización post-incendio de las cortezas quemadas de los alcornoques (Quercus suber L.), por líquenes epífitos,en los diferentes núcleos del alcornocal valenciano-castellonense (Asplenio onopteridis-Querco suberis sigmetum). Estos bosques, afectados por incendios diferentes, se localizan en las Sierras de Espadán y Calderona y en el Desierto de las Palmas y difieren en sus condiciones bioclimáticas, en la estructura del bosque y, consecuentemente, en la composición florística de las comunidades previas a los incendios. El objetivo de este trabajo es conocer el estado de la recolonización e identificar que factores podrían estar implicados en el proceso. La riqueza específica y la cobertura de las comunidades epífitas muestra asimetrías importantes entre áreas. Estas diferencias se relacionan con la proximidad de zonas inalteradas, que deben actuar como inóculo, y con las características bioclimáticas de cada territorio. En total, se han identificado 40 especies liquénicas: 18 crustáceas (45%), 18 foliáceas (45%) y 4 fruticulosas (10%). La sucesión secundaria está dominada por especies de amplia tolerancia ecológica que poseen estructuras de multiplicación vegetativa. Hyperphyscia adglutinata, Physcia adscendens, Ph. tenella y Scoliciosporum chloroccocum son las que aparecen más tempranamente y las más ampliamente representadas; otras, como Evernia prunastri, P. tiliacea, P. soredians,P. subrudecta, Ramalina farinacea, etc., aparecen con mayor frecuencia y desarrollo en los alcornocales que sufrieron un incendio menos intenso y con ombroclima subhúmedo.The post-fire colonization of the burned barks of cork-oaks (Quercus suber L.) by epiphytic lichens affected by fire episodes has been studied in different areas of the Valenciano-castellonense cork-oak forests (Asplenio onopteridis-Querco suberis sigmetum). These forests, which have been affected by fires of different intensity, are located in Espadán and Calderona mountains and in the Desierto de Las Palmas and differ with respect to their bioclimate and forest structure. This facts result in a different floristic composition of the epiphytic communities prior to the occurrence of fires. The aim of this paper is to determine the recolonization state and to identify the factors involved in the process. Specific richness and coverage of the epiphytic communities show differences between areas. These differences are related with the proximity to undisturbed areas and with its bioclimatic characteristics. 40 species have been identified: 18 crustose (45%), foliose (45%) and 4 fruticose lichens (10%). Secondary succession is dominated by species with wide ecological tolerance with soredia or isidia. Hyperphyscia adglutinata, Physcia adscendens, Ph. tenella and Scoliciosporum chloroccocum show the greatest colonization success; others, such as Evernia prunastri, P. tiliacea, P. soredians, P. subrudecta, Ramalina farinacea, etc., show higher frequency and thallus development in forests which were affected by less intense fires and with subhumid ombroclimate

Formation of photosystem II reaction centers that work as energy sinks in lichen symbiotic Trebouxiophyceae microalgae

21 p.Lichens are poikilohydric symbiotic organisms that can survive in the absence of water. Photosynthesis must be highly regulated in these organisms, which live under continuous desiccation-rehydration cycles, to avoid photooxidative damage. Analysis of chlorophyll a fluorescence induction curves in the lichen microalgae of the Trebouxiophyceae Asterochloris erici and in Trebouxia jamesii (TR1) and Trebouxia sp. (TR9) phycobionts, isolated from the lichen Ramalina farinacea, shows differences with higher plants. In the presence of the photosynthetic electron transport inhibitor DCMU, the kinetics of Q(A) reduction is related to variable fluorescence by a sigmoidal function that approaches a horizontal asymptote. An excellent fit to these curves was obtained by applying a model based on the following assumptions: (1) after closure, the reaction centers (RCs) can be converted into "energy sink" centers (sRCs); (2) the probability of energy leaving the sRCs is very low or zero and (3) energy is not transferred from the antenna of PSII units with sRCs to other PSII units. The formation of sRCs units is also induced by repetitive light saturating pulses or at the transition from dark to light and probably requires the accumulation of reduced Q(A), as well as structural changes in the reaction centers of PSII. This type of energy sink would provide a very efficient way to protect symbiotic microalgae against abrupt changes in light intensity.Ministerio de Ciencia e InnovaciónMinisterio de Economía y CompetitividadGeneralitat ValencianaUniversidad de AlcaláComunidad de Madri

Preliminary assessment of terrestrial microalgae isolated from lichens as testing species for environmental monitoring: Lichen phycobionts present high sensitivity to environmental micropollutants

Bioassays constitute a tool for pollution analysis providing a holistic approach and high-quality indication of the toxicity. Microbioassays allow evaluating the toxicity of many samples, implying lower costs and enabling routine monitoring and pollution control. But tests conducted so far are limited to the use of a small number of taxa. Lichens are excellent bioindicators of pollution with great ecological significance. Studies show that the phycobiont is more sensitive to pollutants than the mycobiont. Phycobiont have features such as adaptation to anhydrobiosis and relatively rapid growth in vitro, making them suitable for microbioassays. Our aim is to determine the sensitivity of phycobionts to the pharmaceutical micropollutants carbamazepine and diclofenac as a preliminary step for the development of a toxicity microbioassay based on phycobionts. Optical dispersion and chlorophyll autofluorescence were used as endpoints of toxicity on two algal species showing that suspensions present cyclic and taxon specific patterns of aggregation. Trebouxia TR9 suspensions present a very high grade of aggregation while Asterochloris erici cells do not. Both micropollutants alter optical properties of the suspensions of both species. No significant alteration of chlorophyll autofluorescence by carbamazepine is observed. A. erici chlorophyll autofluorescence is extremely sensitive to diclofenac but the effect is not dependent on the drug concentration or on the time of exposure. Differently, TR9 only shows punctual chlorophyll alterations. Fluctuations in optical dispersion may indicate changes in the population structure of the species, including reproductive strategy. A. erici seems more sensitive to micropollutants, is better characterized and is available from commercial collections

Presence of multiple group I introns closely related to bacteria and fungi in plastid 23S rRNAs of lichen-forming Trebouxia

The chloroplast-encoded large subunit ribosomal RNA gene of several free-living green algae contains group I introns at Escherichia coli genic positions 1917, 1931, 1951, and 2449. Herein we report the presence of group I introns at these positions within the chloroplast-encoded large subunit ribosomal RNA gene of several lichen-forming green algae belonging to the Trebouxia genus. In contrast to the introns inserted at position 2449, all introns inserted at positions 1917, 1931, and 1951 contained LAGLIDADG homing endonuclease genes. Phylogenetic analyses show that: (i) introns inserted at positions 1917, 1931, and 1951 are closely related to introns located at homologous insertion sites in bacterial rDNA genes; and (ii) introns inserted at position 2449 are closely related to fungal introns located at homologous insertion sites in mitochondrial rDNA genes. The symbiogenetic thalli of some lichens are proposed as the likely setting of horizontal transfer of genetic material among distantly related organisms such as bacteria, fungi, and green [email protected]; [email protected]

Trebouxia lynnae sp. nov. (Former Trebouxia sp. TR9): Biology and Biogeography of an Epitome Lichen Symbiotic Microalga

[EN] Simple Summary In this work, we present the formal description of a new species of lichen photobiont (i.e., Trebouxia lynnae) isolated from the lichen Ramalina farinacea. The findings reported here provide an exhaustive characterization of the cellular ultrastructure, physiological traits and genetic and genomic diversity of the new species. Our results contribute to the knowledge of lichen-forming symbiotic green microalgae with their diversity and distribution. Two microalgal species, Trebouxia jamesii and Trebouxia sp. TR9, were detected as the main photobionts coexisting in the thalli of the lichen Ramalina farinacea. Trebouxia sp. TR9 emerged as a new taxon in lichen symbioses and was successfully isolated and propagated in in vitro culture and thoroughly investigated. Several years of research have confirmed the taxon Trebouxia sp. TR9 to be a model/reference organism for studying mycobiont-photobiont association patterns in lichen symbioses. Trebouxia sp. TR9 is the first symbiotic, lichen-forming microalga for which an exhaustive characterization of cellular ultrastructure, physiological traits, genetic and genomic diversity is available. The cellular ultrastructure was studied by light, electron and confocal microscopy; physiological traits were studied as responses to different abiotic stresses. The genetic diversity was previously analyzed at both the nuclear and organelle levels by using chloroplast, mitochondrial, and nuclear genome data, and a multiplicity of phylogenetic analyses were carried out to study its intraspecific diversity at a biogeographical level and its specificity association patterns with the mycobiont. Here, Trebouxia sp. TR9 is formally described by applying an integrative taxonomic approach and is presented to science as Trebouxia lynnae, in honor of Lynn Margulis, who was the primary modern proponent for the significance of symbiosis in evolution. The complete set of analyses that were carried out for its characterization is provided.PROMETEO 2021/005 (Excellence in research, Generalitat Valenciana) and the Grants New Generation EU (Ministry of Universities) to Salvador Chiva (MS21-058) and Cesar Bordenave (ZA21-046)Barreno, E.; Muggia, L.; Chiva, S.; Molins, A.; Bordenave, C.; García-Breijo, F.; Moya, P. (2022). Trebouxia lynnae sp. nov. (Former Trebouxia sp. TR9): Biology and Biogeography of an Epitome Lichen Symbiotic Microalga. Biology. 11(8):1-19. https://doi.org/10.3390/biology1108119611911