Peltigera Praetextata Research Articles

Determination of phytochemical contents by LC/QTOF/MS and evaluation of in-vitro biological activities of 2 Peltigera lichens from Bursa.

Lichens are symbiotic associations of algae and fungi. They are edible as food and have been used in traditional medicine for years. It is aimed to screen Peltigera praetextata (Flörke ex Sommerf.) Zopfand and Peltigera elisabethae Gyeln. phytochemically by LC/QTOF/MS and according to the constituents to evaluate the antioxidant, tyrosinase inhibitory, and antibacterial activities. In total 54 of metabolites detected by LC/QTOF/MS were common in both species. According to LC/QTOF/MS scanning results, alkaloids, iridoid glycosides, phenolics, cyanogenetic glycosides, and terpenic structures were detected. DPPH, ABTS, superoxide radical scavenging activities, and metal chelating capacity IC50 values were 84.55, 9.349; 51.27, 9.127; 95.01, 58.65 and 20.57, 70.08 µg/mL., respectively. The CUPRAC reducing power was determined as 4.69 and 9.57 TEACCUPRAC, respectively. Tyrosinase inhibitor activity were found to be 86.95 and 196.7 µg/mL. Both lichens did not show antimicrobial effects. As a result of the antioxidant and tyrosinase inhibitor activities it was seen that their activities were significant and further in vivo studies could be carried out on this lichens.

Активность супероксиддисмутазы и каталазы в лишайниках с разным составом фотобионтов

Data on the activity of catalase and superoxide dismutase in the thalli of the cyanolichen Peltigera praetextata and the green algal lichen Hypogymnia physodes (See Fig. 1) at different ontogenetic conditions are not available in the literature. At the same time, the study of antioxidant system of lichen thalli with different photobionts during ontogenesis is relevant and can contribute to understanding the mechanisms of adaptation of symbionts to changing environmental conditions, and also serve as indicators of the functional state of the organism. The aim of the study was to investigate the activity of catalase and superoxide dismutase enzymes in lichen thalli P. praetextata and H. physodes at different stages of ontogenesis. P. praetextata and H. physodes thalli samples were collected from aspen and pine trunks under similar ecological conditions of mixed aspen-spruce communities in the middle taiga (62°15'15.9'' N, 33°58'746.1'' E, 61°50'17'' N, 34°23'13'' E, the Republic of Karelia) and northern taiga (64°34'13.9' 'N, 43°15'48'' E, Arkhangelsk Oblast, 64° 33'19'' N, 30°20'46'' E, the Republic of Karelia). Based on morphological features, thalli samples were divided into groups of different age. P. praetextata thalli were divided into 3 groups: virginal (pregenerative, young thalli without reproduction structures), generative (thalli with apothecia and phyllidia – structures of vegetative reproduction), and senile thalli (thalli with signs of degradation over a larger area). H. physodes thalli were divided into 2 groups: virginil and senile thalli; generative thalli with apothecia are extremely rare in the study areas. Catalase activity measured based on enzymatic degradation of hydrogen peroxide, superoxide dismutase activity was determined spectrophotometrically by inhibition of photoreduction of nitroblue tetrazolium, protein content was determined by the method Bradford. Statistical analysis of the data was carried out using one-way analysis of variance. The protein content (mg/g dry mass) in P. praetextata thalli within the studied sample averaged 1.12 ± 0.09, in H. physodes thalli – 2.45 ± 0.32. The activity of superoxide dismutase (units/mg of protein) in thalli of P. praetextata reached an average of 0.34 ± 0.12, in thalli of H. physodes – 0.09 ± 0.01. The values of catalase activity (µmol H2O2/µg protein) in P. praetextata thalli averaged 2.06 ± 0.48, H. physodes – 0.49 ± 0.07. For the thalli of the cyanolichen P. praetextata, a lower (2 times) protein content (See Fig. 2) and a higher (4-5 times) activity of superoxide dismutase (See Fig. 3) and catalase (See Fig. 4) were found in compared with the chlorobiont lichen H. physodes. The species P. praetextata belongs to the group of cyanolichens, and its photobiont is cyanobacteria of the genus Nostoc located in the algal layer of the thallus. In both lichen species, the maximum values of catalase activity were established for virginal thalli, and the minimum values for senile thalli. Perhaps this is due to the high intensity of "growth respiration" of young lichen thalli, which leads to the formation of reactive oxygen species. Differences in the activity of superoxide dismutase in thalli of different ontogenetic stages in the studied species were not shown. In the thalli of P. praetextata and H. physodes, the activity of catalase in thalli from the northern taiga communities is higher than in the thalli of the middle taiga, while the activity of superoxide dismutase, on the contrary, was on average higher in the lichen thalli of the middle taiga. This might be due to variability in the intensity of photosynthesis and respiration along the latitudinal gradient. In lichens, catalase activity can be a marker of mycobiont respiration, and superoxide dismutase activity is a marker of photobiont photosynthesis. The question of contribution of the fungal or algal components of the lichen thallus to the activity of antioxidant enzymes remains open.

Impact of Peltigera praetextata on zucchini grown in weathered p,p'-DDE-contaminated soil and its responses

Impact of Peltigera praetextata on zucchini grown in weathered p,p'-DDE-contaminated soil and its responses

Анатомо-морфологические и физиологические особенности талломов цианолишайника Peltigera praetextata (Florke ex Sommerf.) Zopf разных онтогенетических состояний

The goal of this study is to describe the cyanolichen Peltigera praetextata ontogenesis stages and reveal some of their morphological, anatomical, and physiological features. This paper analyzes 300 P. praetextata thalli taken in 2019 from aspen trunks in the aspen-spruce communities of the middle taiga territory in Kivach Nature Reserve (62°15'15.9'N, 33°58'746.1"E) from permanent sample plots. The authors determined the ontogenetic state of each thallus based on morphology and anatomy data using the concept of a discrete approach to the description of ontogenesis (Suetina, 2001). They registered the following thalli parameters: length, width, presence and length of rhizines, presence and width of veins, presence of phyllidia and apothecia, number of notches and lobes, shape, edge curl, and surface tomentum. They studied the anatomical parameters (thallus total thickness, tomentum thickness, cortical layer, algal layer and medulla thickness, algae cell size) using sections of thalli samples in all ontogenetic states from the apical, medial, and basal parts in triplicate. They measured the content of photosynthetic pigments spectrophotometrically with preparation of alcoholic extracts. To assess the parameters of the water regime of thalli having different ontogenetic states, the authors calculated a specific thallus mass (STM) and water holding capacity (WHC). They made a statistical data measurement using one-way ANOVA and regression analysis. They also calculated the coefficient of variation (CV) to assess the variability of the features under study. The study identified four periods and 12 ontogenetic states of P. praetextata: latent (sp), pre-generative (pr, prt, j, iml, im2, im3, vl, v2), generative (g), and post-generative (ss, s). The values of the morphological and anatomical parameters of the thalli increase during their development. The early ontogenesis stages demonstrate the highest variability of the parameters. The highest variability of the thallus structures under study within the ontogenetic states is registered for the rhizine length, vein width, and medulla thickness, while the highest constancy is typical of the share of the algal layer in the thallus that varies within a very limited range (22-32%) and reaches the minimum values in the post-generative period. The mycobiont increases in volume through a medulla growth. The physiological characteristics of the P. praetextata thalli differ in various ontogenetic states, while the generative thalli characterized by a normal ratio of photosynthetic pigments, maximum water saturation, and maximum water holding capacity have the maximum values. Thus, at early development stages, the thalli demonstrate a lower ability to retain moisture and may represent a critical stage in a lichen life cycle. On the one hand, the revealed wide variability of the morphological and anatomical parameters of young thalli testifies to their high adaptability, but the physiological parameters of water saturation indicate the vulnerability of these stages. These parameters confirm the validity of the ontogenetic stages identified. The paper contains 5 Figures, 5 Tables and 55 References. The Authors declare no conflict of interest.

Antimicrobial and antioxidant potentials of non-cytotoxic extracts of corticolous lichens sampled in Armenia

Due to wide range of secondary metabolites, lichens were used from antiquity as sources of colorants, perfumes and medicaments. This research focuses on exploring the antioxidant, antimicrobial and cytotoxic activities of methanol, ethanol, acetone extracts and aqueous infusions of corticolous lichens sampled from Armenia. Methanol, ethanol and acetone extracts from all tested lichens were active against Gram-positive bacterial strains. The most effective solvent to retrieve antimicrobial compounds was methanol. Aqueous infusions of tested lichens didn’t show any significant antibacterial and antifungal activity. The highest antimicrobial activity was observed for methanol extract of Ramalina sinensis. The minimum inhibitory concentration of methanol extract of Ramalina sinensis were 0.9–1.8 mg mL− 1. Pseudevernia furfuracea demonstrated antifungal activity (Ø 12 mm). Methanol extract of Parmelia sulcata demonstrated largest 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity (71 %). The cytotoxicity was measured on human HeLa (cervical carcinoma) cell lines using microculture tetrazolium test assay. The IC50 values estimated for methanol extracts of Peltigera praetextata, Evernia prunastri, Ramalina sinensis and Ramalina farinacea species in HeLa cell line were within 1.8–2.8 mg mL− 1 and considered as non-cytotoxic. Obtained results suggest that studied lichens can be prospective in biotechnologies as alternative sources of antimicrobial and antioxidant substances.

Техногенный ландшафт как средоточие разнообразия редких видов лишайников в Центральном Черноземье

Цель – первое лихенологическое обследование техногенных отвалов Михайловского горно-обогатительного комбината (Железногорский район, Курская область) с прилегающими природными и урбанизированными территориями. Материалы и методы. Сборы материалов проводились маршрутным методом в течение 2017 и 2019-2020 годов, камеральная обработка осуществлялась с применением общепринятых лихенологических методик. Идентифицированные образцы хранятся в гербариях Центрально-Черноземного заповедника им. проф. В. В. Алехина и Станции юных натуралистов г. Железногорска. Результаты и обсуждение. Выявленная лихенобиота включает 88 видов (преимущественно макролишайников, вследствие методики сбора) из 38 родов, 18 семейств. Наиболее распространенные, металл-толерантные виды: геоплезные Cladonia fimbriata, C. coniocraea, эпигеидные C. rei, C. mitis, C. cornuta, C. furcata, C. phyllophora и C. gracilis, эпифито-эпиксильные Evernia prunastri, Parmelia sulcata, Xanthoria parietina, Hypogymnia physodes и Physcia adscendens. Составлен аннотированный список в различной степени редких видов, среди которых 4 новых для Центрального Черноземья (Cladonia cervicornis, Dibaeis baeomyces, Usnea dasopoga, U. lapponica); 5 новых для Курской области (Bryoria fuscescens, Cladonia carneola, C. deformis, Melanohalea septentrionalis, Peltigera extenuata); 6 занесенных в Красную книгу Курской области (Cladonia subrangiformis, C. subulata, Peltigera praetextata, Platismatia glauca, Pseudevernia furfuracea и Usnea subfloridana); еще 5 редки в области или на более обширных территориях (Acarospora veronensis, Protoparmeliopsis muralis, Ramalina pollinaria, Trapelia coarctata, Usnea hirta). Сосредоточение значительного числа редких видов в техногенных ландшафтах, по-видимому, обусловлено рядом причин: наличием крупных выходов редкого в области и Центральном Черноземье субстрата (ожелезненного песчаника); слабой конкуренцией со стороны сосудистых растений на бедных и обогащенных металлами почвах и грунтах; ботанико-географическим положением территории; спецификой локального загрязнения среды, представленного преимущественно «кислыми» поллютантами и частицами металлов. Заключение. Отмечена приуроченность регионально редких кустистых и листоватых эпифитов из экологической группы ацидофилов к насаждениям березы в изученных техногенных ландшафтах. Предложены некоторые меры охраны выявленных редких видов лишайников.

Vitality of the cyanolichen Peltigera praetextata exposed around a cement plant (SW Slovakia): a comparison with green algal lichens

AbstractThe suitability of the cyanolichen

Application of molecular markers to detect DNA damage caused by environmental pollutants in lichen species.

Pseudevernia furfuracea L. (Zopf), Peltigera praetextata (Flörke ex Sommerf.) Zopf, Lobaria pulmonaria (L.) Hoffm., and Usnea longissima Ach. lichen species were used as bioindicators to assess the genotoxicity of air pollutants. In the present study, we examined significant environmetal pollutants and investigate how changes may lead to damage in DNA structure using RAPD markers. In the study area (Erzurum, Turkey), poor-quality lignite, which generates a large amount of sulfur dioxide, nitrogen oxides, and particle matter, is used for domestic heating, and vehicles also contribute to air pollution. Control lichen samples were collected far from large urban and industrial settlements and transplanted to four polluted sites for 4, 8, or 12 months. The total soluble protein content of the examined four lichen species did not significantly change with exposure time (P < 0.05). The four lichen samples exposed to the pollutants for 8 months had the highest ratio of DNA changes. The ratio of band differences in P. praetextata was higher than that in the other three lichen species, possibly because it has broad leaves that accumulated more pollutants. The average incidences of polymorphism were 64.14, 54.58, 65.76, and 43.06% for P. furfuracea, P. praetextata, L. pulmonaria, and U. longissima, respectively. The genomic template stability (GTS) significantly decreased following exposure to pollutants. GTS ratios revealed that the highest value (98.36%) belonged to U. longissima samples from Site 1 (10 m) after 4 months of exposure, and the lowest values belonged to P. praetextata (73.58%) from Site 3 (100 m) after 8 months of exposure. Based on our findings, we recommend the use of P. praetextata as an indicator of genotoxicity.

Unequal allocation of excitation energy between photosystem II and I reduces cyanolichen photosynthesis in blue light.

Photosynthesis was compared in two cyanobacterial lichens (Lobaria hallii and Peltigera praetextata) and two green algal lichens (Lobaria pulmonaria and Peltigera leucophlebia) exposed to red, green or blue light. Cyanolichens had substantially lower photosynthetic CO(2) uptake and O(2) evolution than the green algal lichens in blue light, but slightly higher photosynthesis in red and green light. The effective quantum yield of photosystem (PS) II (Φ(PSII)) decreased with increasing red and green light for all species, but in blue light this response occurred in green algal lichens only. Cyanolichen Φ(PSII) increased with increasing blue light at low irradiances, but decreased at stronger exposures. However, after adding red light the efficiency of blue light for photosynthetic O(2) evolution increased by 2.4 times. Because phycobilisomes associated with PSII have a low blue light absorption, our results are consistent with blue light absorption mainly by Chl in PSI. Thereby, unequal allocation of excitation energy between PSII and PSI results in low cyanolichen photosynthesis under blue light. This is new knowledge in the science of lichenology with important implications for e.g. the reliability of using Chl fluorometers with blue light for cyanolichens.

Water relation parameters of six Peltigera species correlate with their habitat preferences

Water relation parameters were measured in six congeneric lichen species with different requirements for water availability and with green algae (Peltigera aphthosa, Peltigera leucophlebia, Peltigera venosa) or cyanobacteria (Peltigera horizontalis, Peltigera praetextata, Peltigera rufescens) as main photobionts. Pressure–volume analysis was performed with a dewpoint hygrometer and integrated with anatomical analyses. The Peltigera species typical of arid environments were characterized by relatively lower osmotic potential (π0) and turgor loss point (ΨTLP), and higher values of bulk modulus of elasticity (ɛ). Both π0 and ΨTLP were correlated with the size of medullary cells, while ɛ was negatively correlated with cell dimensions. The adaptive value of low ΨTLP might reside in the capability to maintain cell turgor for longer time intervals under dry conditions. High ɛ might allow xerophilous lichens to regain cell turgor more promptly even for small amounts of water uptake, thus enlarging the cumulative period of positive carbon balance in environments with fluctuating water availability. The influence of the photobiont type is also discussed.

N2 fixation estimates in real-time by cavity ring-down laser absorption spectroscopy

The most common currency for estimating N(2) fixation is acetylene reduction to ethylene. Real-time estimates of nitrogen fixation are needed to close the global nitrogen budget and these remain a critical gap in both laboratory and field experiments. We present a new method for continuous real-time measurements of ethylene production: Acetylene Reduction Assays by Cavity ring-down laser Absorption Spectroscopy (ARACAS). In ARACAS, air in the headspace of an incubation chamber is circulated with a diaphragm pump through a cavity ring-down ethylene spectrometer and back to the incubation chamber. This paper describes the new approach and its benefits compared to the conventional detection of ethylene by flame ionization detector gas chromatography. First, the detection of acetylene reduction to ethylene is non-intrusive and chemically non-destructive, allowing for real-time measurements of nitrogenase activity. Second, the measurements are made instantaneously and continuously at ppb levels, allowing for observation of real-time kinetics on time intervals as short as a few seconds. Third, the instrument can be automated for long time periods of measurement. Finally, the technique will be widely accessible by the research community as it can be readily adapted to most existing acetylene reduction protocols and is based on a modestly priced, commercially available instrument. We illustrate its use for measuring N(2) fixation using two species, the diazotrophic bacterium Azotobacter vinelandii and the lichen Peltigera praetextata. We also discuss potential limitations of the approach, primarily the implications of leaks in the analyzer, as well as future improvements.

The In Vitro Antioxidant Properties of Chinese Highland Lichens

Antioxidant properties of 46 lichen species collected from high-UV exposed alpine areas of southwestern China were evaluated for their therapeutic utilization. Anti-linoleic acid peroxidation activity, 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging activity, reducing power and the total phenolic contents were assessed in methanol extract of the lichens in vitro. Extracts of Peltigera praetextata and Sticta nylanderiana exhibited potent activity in all antioxidant tests. Especially, extracts of S. nylanderiana exhibited 1.37 times higher anti-linoleic acid peroxidation activity than ascorbic acid used as a positive control. It also showed the strongest free radical scavenging activity among all the tested species with an inhibition of 90.4% at the concentration of 330microgram/ml. Potent reducing power was also detected in the lichen extract compared with BHA. Generally, the antioxidant lichens contained large amount of phenolic contents. The activity-guided bioautographic TLC and HPLC analysis are used to find out the compounds responsible for the potent antioxidant activities of S. nylanderiana extract. The analysis demonstrated that lecanoric acid is one of the effective antioxidant compounds in S. nylanderiana. The results suggested that several highland lichens can be used as a novel bioresource for natural antioxidants.

The preservation state of the flora and vegetation of the artillery range near the city of Toruń

The floral and phytosociological research conducted between 1998-2001 in the area of the artillery range shows that there are 460 different species, including 363 vascular plants and 96 algae, bryophytes and lichens. The aforementioned count includes 45 taxa that are fully or partially protected. In the investigated area there are 30 species of vascular plants and 13 lichen species endangered to a different extent, referring to the scale of the whole region, for example: Aster amellus, Prunella grandiflora, Bryoria fuscescens, B. subcana, Peltigera praetextata and Ramalina fraxinea.Out of 335 species recorded in the same area by German researchers in the late 19th century and the early 20th century, the occurrence of 270 species was confirmed by our research, which constitutes 80.6%. The following species are considered as extinct, since they were not found again in the area: Adenophora liliifolia, Cephalanthera damasonium, C. rubra, Dracocephalum ruyschiana and Gladiolus paluster. During the one hundred years, which separate the two research projects, 95 new species appeared in the studied area, mostly archaeophytes and kenophytes.According to the phytosociological research, there are 8 plant associations and one plant community in the unforested part of the range. Among the most rare associations, the following should be mentioned: Caricetum arenariae, Caricetum ligericae and Festuco-Koelerietum glaucae. Calamagrostietum epigeji, Corniculario-Corynephoretum, Arctostaphylo-Callunetum are typical associations of this area. The association Scorzonero purpureae-Stipetum joannis and the community of Salix acutifolia-Epipactis atrorubens are the most valuable ones. They will become the most endangered associations if the excessive pressure by the army or the highway construction should cease in the future.To preserve the particularly valuable species and plant associations, new active preservation forms should be introduced in the whole area of the artillery range, especially after cessation of the excessive military exploitation. A part of the artillery range called "Piaski" should be protected as a sanctuary because of the association Scorzonero purpureae-Stipetum joannis, which occurs only here.

The preservation state of the flora and vegetation of the artillery range near the city of Toruń

The floral and phytosociological research conducted between 1998-2001 in the area of the artillery range shows that there are 460 different species, including 363 vascular plants and 96 algae, bryophytes and lichens. The aforementioned count includes 45 taxa that are fully or partially protected. In the investigated area there are 30 species of vascular plants and 13 lichen species endangered to a different extent, referring to the scale of the whole region, for example: Aster amellus, Prunella grandiflora, Bryoria fuscescens, B. subcana, Peltigera praetextata and Ramalina fraxinea.Out of 335 species recorded in the same area by German researchers in the late 19th century and the early 20th century, the occurrence of 270 species was confirmed by our research, which constitutes 80.6%. The following species are considered as extinct, since they were not found again in the area: Adenophora liliifolia, Cephalanthera damasonium, C. rubra, Dracocephalum ruyschiana and Gladiolus paluster. During the one hundred years, which separate the two research projects, 95 new species appeared in the studied area, mostly archaeophytes and kenophytes.According to the phytosociological research, there are 8 plant associations and one plant community in the unforested part of the range. Among the most rare associations, the following should be mentioned: Caricetum arenariae, Caricetum ligericae and Festuco-Koelerietum glaucae. Calamagrostietum epigeji, Corniculario-Corynephoretum, Arctostaphylo-Callunetum are typical associations of this area. The association Scorzonero purpureae-Stipetum joannis and the community of Salix acutifolia-Epipactis atrorubens are the most valuable ones. They will become the most endangered associations if the excessive pressure by the army or the highway construction should cease in the future.To preserve the particularly valuable species and plant associations, new active preservation forms should be introduced in the whole area of the artillery range, especially after cessation of the excessive military exploitation. A part of the artillery range called "Piaski" should be protected as a sanctuary because of the association Scorzonero purpureae-Stipetum joannis, which occurs only here.

Lichen acclimatization on retention trees: a conservation physiology lesson

Summary 1. Green‐tree retention (GTR) has been suggested as a means to effectively support epiphytic lichen species in managed forests, given the low lichen mortality on retention trees in the short term. However, a long‐term perspective requires a physiological understanding of lichen responses to logging. This study compares anatomical, morphological and physiological traits of lichens on retention trees and on intact forest trees. 2. Thalli of nine taxa (Buellia griseovirens, Cladonia digitata, Hypogymnia physodes, Lecanora allophana, Lecanora pulicaris, Lepraria spp., Peltigera praetextata, Pertusaria amara and Phlyctis argena) were sampled from birch Betula spp. and aspen Populus tremula in GTR cuts, where they had previously been reported to survive well, and in adjacent managed forests. In the laboratory, chlorophyll fluorescence parameter Fv/Fm, thickness of the upper cortex, photobiont to mycobiont ratio and (in Lecanora species) the relative area of the apothecia were measured. 3. All the lichen samples collected from GTR cuts appeared alive, but their Fv/Fm was significantly lower, relative areas of the apothecia were larger and the upper cortices of thalli were thicker compared with the samples from adjacent forests. No difference in photobiont to mycobiont ratio was found. These patterns were broadly consistent among species, indicating a common mechanism: while suffering from photoinhibition, the lichens had acclimatized to the open conditions and increased their investment to sexual reproduction in a few years. 4. Synthesis and applications. The study highlights the value of a morpho‐physiological framework for conservation management by pointing out that, in GTR areas, lichen survival is high‐irradiation limited and heavily dependent on phenotypic plasticity. A thin upper cortex may be a common feature of the most sensitive species. To sustain epiphyte populations in managed forests, precautionary harvesting strategies (gradual felling; group‐retention; extended rotations) should be preferred and large‐enough populations should be preserved, even though short‐term studies suggest a high survival of lichens in cut areas.

Accumulation of Heavy Metals from Motor Vehicles in Transplanted Lichens in an Urban Area

Thalli of the lichens Pseudevernia furfuracea, Usnea longissima, Lobaria pulmonaria, and Peltigera praetextata were taken from unpolluted areas and transplanted to a downtown site in Erzurum, Turkey. Heavy metals copper (Cu), chromium (Cr), zinc (Zn), lead (Pb), nickel (Ni), and iron (Fe) were measured after an 8 month exposure period. Changes in the heavy metal concentrations were observed during the exposure period in lichen species and in both locations. Heavy metal concentrations were significantly higher in Peltigera praetextata than the other species at the location nearest to the junction crossroads. Peltigera praetextata may be considered a good indicator. These results can be attributed to the effect of atmospheric pollutants on the transplanted lichens.

Bayesian Mapping of Lichens Growing on Trees

Suitability of trees as hosts for epiphytic lichens are studied in a forest stand of size 25 ha. Suitability is measured as occupation probabilites which are modelled using hierarchical Bayesian approach. These probabilities are useful for an ecologist. They give smoothed spatial distribution map of suitability for each of the species and can be used in detecting high- and low-probability areas. In addition, suitability is explained by tree-level covariates. Spatial dependence, which is due to unobserved spatially structured covariates, is modelled through an unobserved Markov random field. Markov chain Monte Carlo method has been applied in Bayesian computation. The extensive spatial data consist of the occurrences of eight lichen species and one bryophyte on all of the 1253 potential host trees. In addition, coordinates of the trees and several tree characteristics have been recorded. The data have been analysed for four most abundant species: Lobaria pulmonaria, Nephroma bellum, Nephroma parile and Peltigera praetextata. The tree level parameters, subject to estimation, consist of the occurrence probabilities for each tree and for each lichen species. Model validation is discussed in detail and, in addition to Bayesian validation tools, the autologistic model and case-control design based on logistic regression have been suggested for validation of covariate effects. As a result we present suitability maps for the four lichen species. We observed, that among the observed tree covariates, the diameter at breast height (DBH) correlates with lichen occurrence. Our modelling approach has close connections to disease mapping in spatial epidemiology.

Distribution of New Quaternary Ammonium Compounds, Solorinine and Peltigerine, in the Peltigerales

A new amino acid solorinine [1] having a quaternary ammonium structure that we had previously isolated from the lichen Solorina crocea (L.) Ach., collected in Canada, was contained in all specimens of S. crocea from Europe and North America as well as from Japan. Solorinine was detected in all species of Solorina and Peltigera, both members of the Peltigeraceae; however, it was not detected in species of the Nephromataceae. Another new amino acid, peltigerine [2], isolated from Peltigera praetextata (Florke) Vain., was detected only in species of Peltigera. The structure of peltigerine was determined by spectroscopic methods. All living organisms need water, however, water is difficult obtain under water deficient conditions such as high salinity, drought, or low temperature (Bohnert et al. 1995). Organisms adapt to such environments in numerous ways; accumulation of compatible solutes is one such mechanism. Quaternary ammonium compounds such as glycine betaine are well known to function under water deficient conditions and are found in salt tolerant plants, marine algae, and cyanobacteria (GabbyAzaria et al. 1988; Rhodes & Hanson 1993). Many lichens survive water deficient environments. However, the question, of what mechanisms lichens use remains unanswered. There are a few reports of sugar alcohols as compatible solutes in lichens (Chapman et al. 1994; Feige 1975). Recently, we found a new amino acid, solorinine (2-trimethylamino-4-(3,5-dimethoxy-4hydroxyphenyl)butanoate), (Fig. 1) from Solorina crocea (L.) Ach. (Matsubara et al. 1994). This compound has a quaternary ammonium structure similar to that of glycine betaine. The content of solorinine was about 1 mg g DW-1 (unpublished result), which was equal to that of quaternary ammonium compounds in higher plants (Rhodes & Hanson 1993). These results suggest that solorinine could have a physiological role under water deficient conditions in many species of lichens. Here we report on the distribution of solorinine in lichens of the Peltigerales. Another amino acid, a solorinine analogue, was also isolated and investigated for its distribution. MATERIALS AND METHODS The specimens employed for detection of solorinine are listed in Tables 1-2. Specimens were dried and then stored in the herbarium of Nippon Paint Co. Ltd. (Osaka, Japan) or K chi Gakuen College (Kochi, Japan). Species used are as follows: Nephroma arcticum (L.) Torss., N. bellum (Spreng.) Tuck., N. resupinatum (L.) Ach., N. tropicum (Mill. Arg.) Zahlbr., Peltigera aphthosa (L.) Willd., P. canina (L.) Willd., P. degenii Gyeln., P. dilacerata (Gyeln) Gyeln., P. dolichorrhiza (Nyl.) Nyl., P. elizabethae Gyeln., P. leucophlebia (Nyl.) Gyeln., P. nigripunctata Bitt., P. polydactyla (Neck.) Hoffm., P. praetextata (Fldrke) Vain., P. pruinosa (Gyeln.) Inum., P. rufescens (Weis.) Humb., P. scabrosa Th. Fr., P. spuria (Ach.) DC., Solorina crocea (L.) Ach., S. octospora Arnold, S. platycarpa Hue, S. spongiosa (Sm.) Anzi, and S. saccata (L.) Ach. Each dry lichen thallus (ca 0.5 g) was extracted twice with 100 ml of CHCl3 at room temperature overnight and then twice with 100 ml of MeOH under the same condition. Extraction with CHCl3 was carried out in order to remove constituents of low polarity, which might influence on Rf-values of amino acid derivatives on TLC analysis. Each methanol solution was concentrated under reduced pressure to yield the dried extract. A MeOH extract of each lichen thallus was examined for the presence of solorinine by TLC plate (MERCK DC-Alufolien Kieselgel 60 no. 5553 F254) with high polarity solvent (CHCl3MeOH-HiO, 6:4:1) TLC in comparison with the authentic compound previously isolated (Matsubara et al. 1994). The spot of the quaternary ammonium compound on TLC was clear regardless of the sample freshness, and showed weak violet with both short wave (254 nm) and long wave (365 nm) UV radiation or red after spraying with 10% sulfuric acid and heating at 110oC. Detection of the new amino acid reported in this paper was also done the same way with solorinine using the authentic sample isolated below. Both solorinine and the new amino acid could not 0007-2745/99/196-199$0.55/0 This content downloaded from 207.46.13.115 on Sat, 08 Oct 2016 05:29:28 UTC All use subject to http://about.jstor.org/terms 1999] MATSUBARA ET AL.: NEW AMMONIUM COMPOUNDS 197 +N(CH3)3 N(CH3)2 H3CO .HC O COO H3CO COOH

Intra-specific variation in the photosynthetic responses of cyanobiont lichens from contrasting habitats.

The photosynthetic properties of cyanobiont lichens from contrasting habitats were measured to identify whether the increased assimilation rates which characterized Peltigera membranacea (Ach.) Nyl. from an exposed habitat were correlated with increased carbon-concentrating mechanism (CCM) activity. The results were contrasted with data obtained from two populations of Peltigera praetextata (Flörke ex Sommerf.) Zopf collected from dry and damp microhabitats within a shaded woodland and Peltigera leucophlebia (Nyl.) Gyelnik, which has been shown to lack a carbon-concentrating mechanism. The differences in assimilation rates between the cyanobiont lichens were not accounted for by differences in chlorophyll content. Peltigera membranacea from the exposed habitat which had the highest assimilation rates had the lowest Gamma; and K0·5 values and accumulated the greatest Ci -pool indicating that increased Ci accumulation contributed towards the higher assimilation rates shown by these species. The convexity of the light response curve for the cyanobiont lichens decreased with increasing assimilation rates. This might have indicated a diversion of electron transport to energize the carbon-concentrating mechanism. The apparent quantum efficiency of CO2 assimilation (ΦCO2 ) was correlated with the genus of lichen photobiont. All cyanobiont lichens had comparable values for ΦCO2 which were greater than that of the tripartite Peltigera leucophlebia. Light compensation points reflected the exposure of the habitats with higher compensation points characterizing the cyanobiont population from the exposed crag and the tri-partite population from the open grassland. Carbon isotope discrimination values for organic matter and measured instantaneously were the same for all cyanobiont lichens and were comparable with values recorded for species with a carbon-concentrating mechanism. Carbon isotope measurements for P. leucophlebia were typical of those recorded for species without a carbon-concentrating mechanism. Variation in source isotope signature and refixation of respiratory CO2 were considered to be significant factors in determining organic matter and instantaneous carbon-isotope discrimination. These factors might have masked any subtle variation in carbon-isotope discrimination which resulted from variable CCM activity. The functional significance of increased carbon-concentrating mechanism activity in cyanobiont lichens occupying exposed habitats is discussed.

Two foliose lichens as microfungal ecological niches

The assemblage of filamentous fungi obtained from two foliose lichens, Parmelia taractica and Peltigera praetextata, collected at the same site in a coniferous forest (Aosta Valley, Italy), was studied. Ten apparently healthy thalli of each species were subjected to four isolation techniques. A total of 117 fungal taxa (67 identified to genus or species) were obtained. Numbers of fungal taxa, numbers of isolates, and diversity indices were significantly different in the two lichens; some fungal taxa were significantly associated with only one species. Multivariate analyses (cluster analysis and principal component analysis) showed a tendency towards grouping of fungal assemblages belonging to the same lichen species. These results indicate that some host specificity exists for the fungal colonizers. The range of isolated fungi included typical colonizers of leaves and the rhizoplane-ectomycorrhizoplane, microhabitats that show some ecological and structural similarities with lichen thalli. Other taxa could be obligately lichenicolous, or even true mycobionts. It is suggested that the inherent selectivity of isolation techniques may lead to underestimation of fungal populations associated in nature with Pa. taractica and Pe. praetextata.