In vitro chemopreventive and cytotoxic effects of Amazon mosses Leucobryum martianum (Hornsch.) and Leucobryum laevifolium (Broth) extracts.

Several bioactive compounds, such as polyphenols, demonstrate low toxicity and prominent effects on cancer cells with antioxidant, anti-inflammatory, and antitumor activities. Such compounds can be found in Amazon mosses Leucobryum martianum (Hornsch.) Hampe ex Müll. Hal. (Hornsch.) and Leucobryum laevifolium (Broth). Antimutagenic assay with Salmonella enterica serovar Typhimurium and cytotoxicity with different eukaryotic cell lines were carried out to screen aqueous, hydroalcoholic, and ethanolic extracts of those Amazon mosses for anticancer potential. The results indicate the capacity of all extracts of both mosses to exert chemopreventive effects against 4-nitroquinoline-N-oxide (4NQO) and 2-aminoanthracene (2-AA), which are direct or indirect mutagens. In particular, the ethanolic and aqueous extract from L. martianum. The ethanolic extract from L. martianum induces significant cytotoxicity by mitochondrial metabolism and cell membrane disruption pathways to tumor or non-tumor cells. The aqueous extract from L. martianum showed a mainly cytotoxic response in the HepG2 cells, a human liver carcinoma, reaching ~90% cytotoxicity. The same extract did not induce significant damage to normal liver cells (F C3H cells) by membrane interaction pathway. The selective cytotoxicity in the aqueous extract of L. martianum makes it a candidate against liver cancer. Further studies, including in vivo models, are necessary to validate the efficacy and safety of the aqueous extract of L. martianum.

The decline of tufa deposition in an alkaline fen ecosystem in East-Central Europe and its impact on biotic assemblages: Insights from monitoring and paleoecological data.

Protection and restoration of the CaCO3 depositing alkaline fens require an in-depth understanding of these unique and declining ecosystems. The present study investigates the development of the formerly heavy tufa depositing alkaline fen in East-Central Europe after CaCO3 precipitation markedly declined ca. 5400 cal yr BP. By combining palaeoecological and monitoring data, we aim to identify the limiting factors for tufa deposition and to recognise the vegetation and mollusc response to the change. Investigation of the current fen ecosystem included a botanical and malacological inventory and a monthly monitoring of the physicochemical properties of the groundwater emerging at the fen. It was also tested whether CaCO3 precipitates there. Transformations of the fen ecosystem since the mid-Holocene tufa decline were recognized by applying plant macrofossil and malacological analyses supplemented with organic matter and CaCO3 contents and the radiocarbon chronologies of the sediment cores. Although macroscopic tufa is currently not observed at the fen surface, the monitoring study revealed the microscopic calcite crystals at the glass slides during the spring and summer. A combination of cooling, gradual depletion of the Ca2+ pool, acidification of soils, and water table fluctuations was likely responsible for limiting tufa deposition in the mid-Holocene and maintaining this state during the late Holocene. Share of the calciphilous species' macrofossils (e.g. moss Tomentypnum nitens) declined following the sedimentary CaCO3 drop, whereas the contribution of species associated with high nutrient levels raised (e.g. Juncus articulatus). Inspection of the contemporary vegetation of the fen revealed that only Carex paniculata is associated with the calcium-rich substrate. The response of molluscs to the decline in tufa deposition remains unclear as mollusc shells did not preserve in CaCO3-depleted sediments, except for the youngest deposits. The present-day malacofauna consists of 21 species, including two rare and protected calciphilous species, namely Vertigo angustior and V. geyeri.

Relationships among sporophytic and gametophytic traits of 27 subtropical montane moss species.

PREMISE: Moss sporophytes differ strongly in size and biomass partitioning, potentially reflecting reproductive and dispersal strategies. Understanding how sporophyte traits are coordinated is essential for understanding moss functioning and evolution. This study aimed to answer: (1) how the size and proportions of the sporophyte differ between moss species with and without a prominent central strand in the seta, (2) how anatomical and morphological traits of the seta are related, and (3) how sporophytic biomass relates to gametophytic biomass and nutrient concentrations. METHODS: We studied the relationships between seta anatomical and morphological traits, the biomass of seta, capsule, and gametophyte, and carbon, nitrogen, and phosphorus concentrations of 27 subtropical montane moss species. RESULTS: (1) Moss species with a prominent central strand in the seta had larger setae and heavier capsules than those without a prominent strand. (2) With increasing seta length, setae became thicker and more rounded for both groups, while in species with a prominent central strand, the ratio of transport-cell area to epidermal area decreased. (3) In both groups, mosses with greater gametophytic biomass tended to have heavier sporophytes, but nitrogen and phosphorus concentrations in the gametophyte were unrelated to sporophytic traits. CONCLUSIONS: Our study highlights that the central strand in the seta may have an important functional role and affect the allometry of moss sporophytes. The coordinated variations in sporophyte morphological and anatomical traits follow basic biomechanical principles of cylinder-like structures, and these traits relate only weakly to the gametophytic nutrient concentrations. Research on moss sporophyte functional traits and their relationships to gametophytes is still in its infancy but could provide important insights into their adaptative strategies.

Study of the Biological Activity and Phenolic Content of the Ethanol Extract of Phyllogonium viride Brid. (Phyllogoniaceae, Bryophyta).

The present study aimed to examine the phenolic content and evaluate the antimicrobial and antioxidant potential of ethanol extracts from the moss species Phyllogonium viride Brid. on the pathogenic bacteria Salmonella enterica serovar enteritidis, Staphylococcus aureus, Listeria monocytogenes and Escherichia coli, and the pathogenic fungi Candida albicans and Cryptococcus neoformans. The antimicrobial activity was determined from Minimum Inhibitory Concentration (MIC) Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC). Antioxidant activity was determined by the DPPH method. Folin-Denis reagent was used for the content of total phenolics and flavonoids and HPLC-DAD for identification of phenolic compounds. The results showed that bacteriostatic and bactericidal activities occurred at concentrations ranging from 9.76 µg/mL-78.13 µg/mL among all evaluated microorganisms. These values, considering the criteria used, suggest the P. viride extract as a potent antimicrobial. For antioxidant activity, P. viride extract was considered weak. Analysis of the phenolic content showed a wide range of compounds, with Kaempferol (0.41 mg/g) being the major compound, followed by t-cinnamic acid and caffeic acid (0.17 mg/g). Although P. viride is a species of moss not yet referenced in scientific publications of biotechnological interest, it has shown promising potential for further studies and possible application as an antimicrobial of natural origin.

Root architectures differentiate the composition of organic carbon in bauxite residue during natural vegetation.

Understanding plant root architectures induced changes in organic carbon accumulation and conversion is critical to predicting carbon cycling and screening appropriate plant species for ecological restoration on bauxite residue disposal areas. According to the ecological investigation of a weathered bauxite residue disposal area, three plants with different root architectures including Artemisia lavandulaefolia (A. lavandulaefolia), moss, and Zanthoxylum simulans (Z. simulans) were selected to investigate the rhizosphere effects on the composition and structure of organic carbon in bauxite residue. The physic-chemical properties, the contents and structure of different organic carbon fractions, and microbial communities of bauxite residue from rhizosphere and non-rhizosphere were analyzed. Plant growth decreased the saline-alkalinity, increased the contents of total organic carbon, particulate organic carbon and dissolved organic carbon, whilst enhancing the enzymatic activities of bauxite residue. Meanwhile, the rhizosphere effects had significant effects on the accumulation and stabilization of organic carbon in bauxite residue. A. lavandulaefolia had the strongest rhizosphere effects on the composition and structure of total organic carbon and dissolved organic carbon, whilst moss was more effective on the accumulation of particulate organic carbon in bauxite residue. Plant growth and root architecture changed the abundance of specific functional microorganisms and the complexity of microbial co-occurrence networks, thus elevating organic carbon levels in bauxite residue. During natural vegetation encroachment, rhizosphere exciting effects of the salt-tolerated plants could change the composition and structure of organic carbon fractions due to the comprehensive effectiveness of the improvement of physic-chemical properties and microbial communities. The findings improve our understanding of the responses of sequestration and stabilization of organic carbon pools to ecological restoration on bauxite residue disposal areas.

C:N:P stoichiometric characteristics of mosses in Picea crassifolia forest in Helan Mountains, Ningxia, China.

To explore the stoichiometric characteristics of C, N and P and adaptive mechanism of mosses in mountain forest ecosystems, we set up 15 plots along the altitude gradient in Picea crassifolia forest in Helan Mountains, Ningxia. We analyzed the C:N:P stoichiometry of moss aboveground tissues and its relationship with environmental factors. The results showed the mean values of C, N and P concentration in moss aboveground tissues were 336.67, 20.31 and 0.66 mg·g-1, respectively. The mean value of aboveground tissue N:P was 33.4, indicating that the growth of mosses was limited by P. The C concentration in the aboveground tissues of mosses was positively correlated with soil total nitrogen concentration and negatively correlated with soil total phosphorus concentration. The N concentration in aboveground tissues of mosses was significantly negatively correlated with soil organic carbon and soil total nitrogen concentrations. Results of redundancy analysis showed that the interpretation rate of environmental factors on the stoichiometry was 48.5%, with canopy closure, soil total nitrogen and soil total phosphorus as the main factors. Canopy closure was the main environmental factor affecting the growth of mosses in P. crassifolia forest in Helan Mountains. High canopy closure facilitated the growth of mosses.

Chemical Stimulation of Heterocyte Differentiation by the Feather Moss Hylocomium splendens: a Potential New Step in Plant-Cyanobacteria Symbioses.

Cyanobacteria associated with mosses play a key role in the nitrogen (N) cycle in unpolluted ecosystems. Mosses have been found to release molecules that induce morphophysiological changes in epiphytic cyanobionts. Nevertheless, the extent of moss influence on these microorganisms remains unknown. To evaluate how mosses or their metabolites influence N2 fixation rates by cyanobacteria, we assessed the nitrogenase activity, heterocyte frequency and biomass of a cyanobacterial strain isolated from the feather moss Hylocomium splendens and a non-symbiotic strain when they were either growing by themselves, together with H. splendens or exposed to H. splendens water, acetone, ethanol, or isopropanol extracts. The same cyanobacterial strains were added to another moss (Taxiphyllum barbieri) and a liverwort (Monosolenium tenerum) to assess if these bryophytes affect N2 fixation differently. Although no significant increases in nitrogenase activity by the cyanobacteria were observed when in contact with H. splendens shoots, both the symbiotic and non-symbiotic cyanobacteria increased nitrogenase activity as well as heterocyte frequency significantly upon exposure to H. splendens ethanol extracts. Contact with T. barbieri shoots, on the other hand, did lead to increases in nitrogenase activity, indicating low host-specificity to cyanobacterial activity. These findings suggest that H. splendens produces heterocyte-differentiating factors (HDFs) that are capable of stimulating cyanobacterial N2 fixation regardless of symbiotic competency. Based on previous knowledge about the chemical ecology and dynamics of moss-cyanobacteria interactions, we speculate that HDF expression by the host takes place in a hypothetical new step occurring after plant colonization and the repression of hormogonia.

[Effects of moss biocrusts on soil-microbe-ectoenzyme stoichiometric characteristics in a subtropical area]. / 亚热带苔藓结皮对土壤-微生物-èƒžå¤–é ¶åŒ–å­¦è®¡é‡ç‰¹å¾çš„å½±å“.

The formation and development of biological soil crusts (biocrusts) potentially affect the cycles and stoichiometric characteristics of soil carbon (C), nitrogen (N), and phosphorus (P). However, it is still unclear how soil microbes adapt to such changes. In this study, we examined the effects of moss-dominated biocrusts coverage (0, 1%-20%, 20%-40%, 40%-60%, 60%-80%, and 80%-100%) on soil physicochemical properties, soil microbial biomass, and ectoenzyme activities [ß-1, 4-glucosidase (BG), ß-1, 4-N-acetyl glucosidase (NAG), acid phosphatase (AP)] in two soil layers (0-5 and 5-10 cm) in the Three Gorges Reservoir area, as well as the covariations of soil-microbe-ectoenzyme C:N:P stoichiometry. The results showed that biocrust development significantly increased soil clay content, water stable aggregates, soil C, N, P contents, and significantly decreased soil bulk density and sand content. Microbial biomass C, N, P and ectoenzyme activities were significantly increased with increasing biocrust coverage. Soil depth did not affect soil physicochemical properties and C:N:P, but significantly affected microbial biomass, ectoenzyme activities, BG:AP and NAG:AP. Soil C, N and P contents were significantly positively correlated with microbial biomass and ectoenzyme activities, negatively correlated with BG:NAG, while positively correlated with NAG:AP, but had no significant correlation with microbial biomass C:N:P. There was no significant correlation between soil-microbe and microbial-ectoenzyme C:N:P. BG:NAG:AP decreased gradually with the increase of C:N:P stoichiometric imbalance between microbe and soil. This study indicated that the microbial metabolism was co-limited by N and P and with stronger P limitation. Microbes could maintain homeostasis by adjusting their own biomass and ectoenzyme C:N:P to adapt to changes in soil ecological stoichiometry driven by biocrust development.

Role of alkaline barriers in radionuclide distribution in river valley environments on the Russian Black Sea coast.

This paper reports on the radioecological properties of environmental components in the Mzymta and Sochi River valleys on the Russian Black Sea coast. The environmental components covered are river sediments, alluvial soils, mosses, and fluvial water. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to determine the distribution patterns of Th and U stemming from two geochemical alkaline barriers present in the river valleys. One is a calcium barrier resulting from the metamorphic transition from neutral mudstones to alkaline carbonate rocks. The other is a sodium barrier formed in estuaries under the influence of Na-rich tidal seawater. The sodium barrier was responsible for an increase in Th and U concentrations in river water, a slight decrease in soil and sediments, and strong sorption on mosses. The calcium barrier reduced Th and U concentrations in river water, but increased them in soil and mosses. In the Sochi River valley, the content of calcium in the components of the natural environment is higher compared to the Mzymta River valley and, on average, 4 times higher in the river water. This factor determines the relatively high Th and U content in the natural environment of the Sochi River valley, as these radionuclides are easily extracted from the mineral component of river water by carbonate solutions. On the whole, the radioecological status of the river valleys was recognized as favourable. Gamma radiation exposure dose rate near the surface (20-27 µR/h or less in mountainous areas and 9-17 µR/h in the lowlands) was below the natural level typical for open mountainous areas of central Russia. River sediments in both valleys had low radionuclide concentrations based on the specific activities of naturally occurring radionuclides 226Ra, 228Ra, 224Ra, 232Th, and 40K. In similar river basins that may be targeted for future development, accumulation of Th and U in soil and mosses on calcium barriers and elevated concentrations in river water on sodium barriers should be expected.

A scoping review of bryophyte microbiota: diverse microbial communities in small plant packages.

Plant health depends not only on the condition of the plant itself but also on its diverse community of microbes, or microbiota. Just like the better-studied angiosperms, bryophytes (mosses, liverworts, and hornworts) harbor diverse communities of bacteria, archaea, fungi, and other microbial eukaryotes. Bryophytes are increasingly recognized as important model systems for understanding plant evolution, development, physiology, and symbiotic interactions. Much of the work on bryophyte microbiota in the past focused on specific symbiont types for each bryophyte group, but more recent studies are taking a broader view acknowledging the coexistence of diverse microbial communities in bryophytes. Therefore, this review integrates studies of bryophyte microbes from both perspectives to provide a holistic view of the existing research for each bryophyte group and on key themes. The systematic search also reveals the taxonomic and geographic biases in this field, including a severe under-representation of the tropics, very few studies on viruses or eukaryotic microbes beyond fungi, and a focus on mycorrhizal fungi studies in liverworts. Such gaps may have led to errors in conclusions about evolutionary patterns in symbiosis. This analysis points to a wealth of future research directions that promise to reveal how the distinct life cycles and physiology of bryophytes interact with their microbiota.

Anti-Inflammatory Activity of Bryophytes Extracts in LPS-Stimulated RAW264.7 Murine Macrophages.

Bryophytes produce rare and bioactive compounds with a broad range of therapeutic potential, and many species are reported in ethnomedicinal uses. However, only a few studies have investigated their potential as natural anti-inflammatory drug candidate compounds. The present study investigates the anti-inflammatory effects of thirty-two species of bryophytes, including mosses and liverworts, on Raw 264.7 murine macrophages stimulated with lipopolysaccharide (LPS) or recombinant human peroxiredoxin (hPrx1). The 70% ethanol extracts of bryophytes were screened for their potential to reduce the production of nitric oxide (NO), an important pro-inflammatory mediator. Among the analyzed extracts, two moss species significantly inhibited LPS-induced NO production without cytotoxic effects. The bioactive extracts of Dicranum majus and Thuidium delicatulum inhibited NO production in a concentration-dependent manner with IC50 values of 1.04 and 1.54 µg/mL, respectively. The crude 70% ethanol and ethyl acetate extracts were then partitioned with different solvents in increasing order of polarity (n-hexane, diethyl ether, chloroform, ethyl acetate, and n-butanol). The fractions were screened for their inhibitory effects on NO production stimulated with LPS at 1 ng/mL or 10 ng/mL. The NO production levels were significantly affected by the fractions of decreasing polarity such as n-hexane and diethyl ether ones. Therefore, the potential of these extracts to inhibit the LPS-induced NO pathway suggests their effective properties in attenuating inflammation and could represent a perspective for the development of innovative therapeutic agents.

Green Christmas: bryophytes as ornamentals in Croatian traditional nativity scenes.

BACKGROUND: The bryophytes are a plant group that is smaller than and not as well known as the vascular plants. They are less used and are almost completely neglected in ethnobotanical studies. Traditional nativity scenes depicting the birth of Christ are commonly decorated with both vascular plants and bryophytes. The aim of this study was to document the diversity of decorative bryophytes sold during the Advent season at farmers' markets in Croatia (Southeastern Europe, Balkan Peninsula). METHODS: Twenty-eight farmers' markets in the two largest Croatian cities (Zagreb in the continental part and Split in the Mediterranean part) were studied in the search for local vendors selling bryophytes during the pre-Christmas season. The bryophytes collected were identified and analysed with respect to families, growth type, life forms and threat status. RESULTS: Among 275 collected specimens, 43 moss and four liverwort species were identified. The mean number of species per vendor was 3.5. The most frequent species were Hypnum cupressiforme, Homalothecium sericeum and Ctenidium molluscum. Mats, wefts and tufts were the most common life-forms, while pleurocarpous prevailed over acrocarpous mosses, as they are usually pinnately branched and form large carpets, suitable for decorations. The overall selection of bryophytes and the decorations made of them were more diverse and abundant in inland Croatia, where 49 vendors at 15 farmers' markets sold goods containing 43 species. In Mediterranean Croatia, at six farmers' markets only 29 vendors sold goods, which contained 18 species. A considerable number of species that are less attractive to harvesters were collected non-intentionally, entangled in carpets of other, more frequent species. Among them, Rhodobryum ontariense and Loeskeobryum brevirostre are rare and insufficiently recorded in Croatia so far. CONCLUSIONS: The present study provided a first perspective on the use of bryophytes in traditional nativity scenes in Croatia and Southeastern Europe, contributing to scarce ethnobotanical documentation of the decorative use of bryophytes in Christmas festivities in Europe and globally.

Cell wall biology of the moss Physcomitrium patens.

The moss Physcomitrium (previously Physcomitrella) patens is a non-vascular plant belonging to the bryophytes that has been used as a model species to study the evolution of plant cell wall structure and biosynthesis. Here, we present an updated review of the cell wall biology of P. patens. Immunocytochemical and structural studies have shown that the cell walls of P. patens mainly contain cellulose, hemicelluloses (xyloglucan, xylan, glucomannan, and arabinoglucan), pectin, and glycoproteins, and their abundance varies among different cell types and at different plant developmental stages. Genetic and biochemical analyses have revealed that a number of genes involved in cell wall biosynthesis are functionally conserved between P. patens and vascular plants, indicating that the common ancestor of mosses and vascular plants had already acquired most of the biosynthetic machinery to make various cell wall polymers. Although P. patens does not synthesize lignin, homologs of the phenylpropanoid biosynthetic pathway genes exist in P. patens and they play an essential role in the production of caffeate derivatives for cuticle formation. Further genetic and biochemical dissection of cell wall biosynthetic genes in P. patens promises to provide additional insights into the evolutionary history of plant cell wall structure and biosynthesis.

Oncophoraceae (Bryophyta): a palynological treatment of species occurring in the Americas.

Oncophoraceae are acrocarpous mosses that predominantly grow as tufts or cushions and especially occur on rocks and soil. The recognition of Oncophoraceae as a distinct family, as well as its generic circumscription, is not consensus among authors, and the pursuit for new information to improve its characterization is incessant. The present work aims to characterize the spore morphology and ultrastructure of 19 species (eight genera) occurring in the Americas and to evaluate the relevance of palynological data to circumscribe species, contributing to support other palynological studies. Observations were performed under Light and Electron (Scanning and Transmission) Microscopes. A Cluster Analysis was performed in order to evaluate the meaning of the palynological data, especially concerning the establishment of the species circumscription. Spores are monads, small to medium sized (10.40 to 44.20 µm), radially symmetric, subcircular in amb, heteropolar or apolar; the surface is ornamented by granules, gemmae and bacula. Anisomorphic spores were observed in eight studied species and are reported herein for the first time. The Cluster Analysis shows two groups with low similarity, which primarily differ by the polarity of the spores. The circumscription of Kiaeria and Cynodontium is corroborated by palynological characterization and endorsed by Cluster Analysis.

Pharmacological, Cytotoxic, Immunostimulant, and Auto-Immune Activity of Thalloid Liverworts: An Overview.

Bryophytes have historically been employed as verdant medicine in China, Native America and India. Phenolics, glycosides, fatty acids, other rare aromatic compounds and Terpenoids found in bryophytes may help prevent cancer and other chronic disorders. Liverworts have historically been utilized in traditional medicine and also as immu-nomodulators or immunostimulants. Diterpenoids, Lipophilic mono-, sesqui- and aromatic compounds assisting to the biological activities of liverworts. For their biological functions more than 220 aromatic compounds and 700 terpenoids and other chemicals discovered in liverworts scrutinized for their pharmacological, cytotoxic, immunostimulant and auto-immune efficacies.

The comparison of the phytochemical composition, antioxidant and enzyme inhibition activity of two moss species: Plagiomnium ellipticum (Brid.) T. Kop. and Antitrichia californica Sull., from southwest ecological region in Turkey.

A limited number of mosses have been studied regarding antioxidant activity and enzyme inhibition effects. In the present study, the phytochemical content, antioxidant, and enzyme inhibition properties of the ether extracts from T.J.Kop.. were investigated as promising bryophyte sources. The ether extracts of P. ellipticum had the highest flavonoid content (52.41 ± 0.52, Rutin equivalent), and A. californica had the highest total phenolic content (25.84 ± 0.23, Gallic acid equivalent). While the P. ellipticum had the highest ABTS (mg TE/g extract) 6.60 ± 0.4); A. californica showed the highest metal chelating capacity (mg EDTA/g extract) with the values of 51.46 ± 0.26. In the enzyme activity tests, almost all values of the species were closed the each other, but P. ellipticum was exhibited higher tyrosinase activity (mg/KAE/g extract) with 48.64 ± 1.02. The results have indicated for the first time the potential importance of the selected mosses.

Cytotoxicity, antimicrobial and antioxidant activities of mosses obtained from open habitats.

Mosses are mainly the object of ecological and taxonomic research. This group of plants are still underestimated by scientists in other aspects of research. Recent research has shown that these plants contain remarkable and unique substances with high biological activity. Five species of mosses from a large urban ecosystem were identified for present study. In order to determine their biological potential, multifaceted studies were carried out, including: total phenolics content, antioxidant activity, antimicrobial and antifungal study, cytotoxicity evaluation, and scratch assay to assess pro-regenerative effect in the context of their possible use as the ingredients of biologically active cosmetics. Additionally, determination of individual phenolic compounds in selected extracts of the tested mosses was made. Research showed that Ceratodon purpureus and Dryptodon pulvinatus extracts had the greatest potential as antioxidants and antimicrobial activity. The cytotoxicity assessment indicated that the extracts from Dryptodon pulvinatus and Rhytidiadelphus squarossus exerted the strongest negative effect on mouse fibroblast line L929 viability at higher concentrations. While, the extract from Tortulla muralis best stimulated human foreskin fibroblast line HFF-1 proliferation and wound healing. The research on individual phenolic compounds content in the extracts tested indicated over 20 peaks on UPLC chromatograms. The conducted study has shown that mosses, especially so far unexplored species of open ecosystems, and e.g. epilytic habitats, may be a valuable source of biologically active substances and thus may constitute important medical and cosmetic possibilities.

Heteromannans are the predominant hemicelluloses in the gametophytic stem of the umbrella moss Hypnodendron menziesii and occur in the walls of all cell types.

MAIN CONCLUSION: Heteromannans are the predominant hemicelluloses in the gametophytic stem of the moss Hypnodendron menziesii and occur in the walls of all cell types Little is known about the cell-wall polysaccharides of mosses. Monosaccharide analysis of cell walls isolated from the stem of the umbrella moss Hypnodendron menziesii was consistent with heteromannans, probably galactoglucomannans, being the predominant hemicellulosic polysaccharides in the walls. Immunofluorescence and immunogold microscopy with the monoclonal antibody LM21, specific for heteromannans, showed that these polysaccharides were present in the walls of all stem cell types. These cell types, except the hydroids, have secondary walls. Experiments in which sections were pre-treated with 0.1 M sodium carbonate and with the enzyme pectate lyase indicated that the heteromannans have O-acetyl groups that limit LM21 binding and the cell walls contain pectic homogalacturonan that masks detection of heteromannans using LM21. Therefore, to fully detect heteromannans in the cell walls, it was essential to use these pre-treatments to remove the O-acetyl groups from the heteromannans and pectic homogalacturonan from the cell walls. Fluorescence microscopy experiments with a second monoclonal antibody, LM22, also specific for heteromannans, showed similar results, but the binding was considerably weaker than with LM21, possibly as a result of subtle structural differences in the epitopes of the two antibodies. Although heteromannans occur abundantly in the cell walls of many species in basal lineages of tracheophytes, prior to the present study, research on the distribution of these polysaccharides in the walls of different cell types in mosses was confined to the model species Physcomitrium patens.

Ecological stoichiometric characteristics of soil-moss C, N, and P in restoration stages of karst rocky desertification.

Rocky desertification is the most serious ecological disaster in karst areas. Comprehensive control of rocky desertification plays an important role in promoting the economic development of karst areas. Studying the stoichiometric characteristics of mosses and soil can provide a powerful reference for the ecological restoration and evaluation of ecosystems experiencing rocky desertification. Soil and mosses were collected from sites representing different stages of ecological restoration (bare rock, grassland, shrubland, and secondary forest), and the contents of carbon (C), nitrogen (N), and phosphorus (P) were detected for ecological stoichiometric analysis. The results indicate that in different restoration stages following karst rocky desertification, the contents of soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) and the stoichiometric ratios in the shrub habitat are higher than those in the bare rock, grassland, and secondary forest habitats. However, the TP and available P contents were low at all stages (0.06 g/kg and 0.62 mg/kg, respectively). The N and P contents and stoichiometric ratios in the mosses showed no significant differences among the succession stages. The C contents in the mosses had a significant positive correlation with SOC and TN and TP content, and the P content had a significant positive correlation with the soil available P. However, there was a significant negative correlation between the C: N and C:P ratios of the bryophytes and soil C: N. In summary, during the process of natural restoration of karst rocky desertification areas, SOC and soil TN contents accumulate with each succession stage. Soil nutrients are higher in shrub habitats than in other succession stages. Mosses have a strong effect on improving soil nutrients in rocky desertification areas.

Chemical characterization and in vitro immunomodulatory effects of different extracts of moss Hedwigia ciliata (Hedw.) P. Beauv. from the Vrsacke Planine Mts., Serbia.

Bioactive compounds from natural sources are of great importance because of their potential pharmacological activity and tremendous structural diversity. In this study, the chemical composition of different moss extracts of Hedwigia ciliata P. Beauv. have been examined, as well as their antioxidant, antineurodegenerative/anti-neuroinflammatory, antidiabetic, and antiproliferative potential. The extracts were prepared by Soxhlet extractor using solvents of different polarity. Chemical characterization of the extracts revealed the presence of phenolics and flavonoid compounds, together with triterpenoids as secondary metabolites of high biological activity. Significant antioxidant properties of all the extracts were exhibited using the ß-carotene assay. The highest activities were found for water:ethanol extract (with the highest inhibition rate of 96%), but also significant inhibition was measured for ethanol and ethyl acetate extracts (80% and 70%, respectively). Confirmation of biocompatibility of investigated moss extracts has been performed using normal human fibroblast cell line, MRC-5. The H. ciliata extracts exhibited significant antiproliferative activity (~ 50%) against the MDA-MB-231 (human breast adenocarcinoma cell line), which has not previously been reported elsewhere. The Griess assay confirmed the potential anti-neuroinflammatory activity of the extracts, as significant effects in reducing NO production by LPS-stimulated BV2 (normal murine microglia cell line) was observed. This data is in line with noted antineurodegenerative potential measured by the inhibition of acetylcholinesterase (with the highest inhibition rate of 60% for ethyl acetate extract) and tyrosinase (with the highest inhibition rate of 70% for ethanol extract). Additionally, the H. ciliata extracts exhibited significant antidiabetic effect mediated by α-glucosidase inhibition (with the highest inhibition rate of 80% for ethyl acetate extract). The obtained data suggest the presence of immunomodulatory effects of the moss extracts in vitro, which allows the design of new experiments aimed at detecting and characterizing bioactive compounds of the extracts and additionally elucidate detailed mechanisms of their effects.