O-methylated N-glycans Distinguish Mosses from Vascular Plants

In the animal kingdom, a stunning variety of N-glycan structures have emerged with phylogenetic specificities of various kinds. In the plant kingdom, however, N-glycosylation appears to be strictly conservative and uniform. From mosses to all kinds of gymno- and angiosperms, land plants mainly express structures with the common pentasaccharide core substituted with xylose, core α1,3-fucose, maybe terminal GlcNAc residues and Lewis A determinants. In contrast, green algae biosynthesise unique and unusual N-glycan structures with uncommon monosaccharides, a plethora of different structures and various kinds of O-methylation. Mosses, a group of plants that are separated by at least 400 million years of evolution from vascular plants, have hitherto been seen as harbouring an N-glycosylation machinery identical to that of vascular plants. To challenge this view, we analysed the N-glycomes of several moss species using MALDI-TOF/TOF, PGC-MS/MS and GC-MS. While all species contained the plant-typical heptasaccharide with no, one or two terminal GlcNAc residues (MMXF, MGnXF and GnGnXF, respectively), many species exhibited MS signals with 14.02 Da increments as characteristic for O-methylation. Throughout all analysed moss N-glycans, the level of methylation differed strongly even within the same family. In some species, methylated glycans dominated, while others had no methylation at all. GC-MS revealed the main glycan from Funaria hygrometrica to contain 2,6-O-methylated terminal mannose. Some mosses additionally presented very large, likewise methylated complex-type N-glycans. This first finding of the methylation of N-glycans in land plants mirrors the presumable phylogenetic relation of mosses to green algae, where the O-methylation of mannose and many other monosaccharides is a common trait.

Biomonitoring of Heavy Metal Air Pollution in Warsaw Using Two Moss Species Pleurozium schreberi and Sphagnum palustre

The aim of the study was to assess air pollution with heavy metals in Warsaw, on the basis of the concentrations of selected elements in moss samples. The active biomonitoring method (moss-bag technique) was applied using two moss species Pleurozium schreberi and Sphagnum palustre. Moss samples were collected in the Kampinos National Park, and the prepared moss bags were distributed and exposed on seven sites in Warsaw. The analysis of metals accumulated in mosses was performed twice in 2020, after two (August-September) and four months (August-November) of exposure. The concentrations of seven heavy metals (Cr, Cu, Pb, Ni, Fe, Cd and Zn) in the mosses were determined, using an Inductively Coupled Plasma Optical Emission Spectrometer (ICP OES). Our results showed a clear dependence of heavy metal accumulation in the mosses on the location of the exposition site and the exposure period. Both species of mosses were found to accumulate the most metals in the vicinity of pollutant emitters, such as the ArcelorMittal Warsaw smelter, exit roads or roads in the city with heavy traffic, petrol stations, or construction works. After 4 months of exposure, in both moss species, the highest increases in the concentrations were found for four elements: Cr, Pb, Ni and Cd. Higher concentrations of some heavy metals in the mosses in 2020, as compared to previous studies, indicate a negative influence of progressing urbanisation on air pollution in Warsaw.

O-methylated N-glycans Distinguish Mosses from Vascular Plants

In the animal kingdom, a stunning variety of N-glycan structures has emerged with phylogenetic specificities of various kinds. In the plant kingdom, however, N-glycosylation appears as strictly conservative and uniform. From mosses to all kinds of gymno- and angiosperms, land plants mainly express structures with the common pentasaccharide core substituted with xylose, core α1,3-fucose, maybe terminal GlcNAc residues and Lewis A determinants. In contrast, green algae biosynthesize unique and unusual N-glycan structures with uncommon monosaccharides, a plethora of different structures and various kinds of O-methylation. Mosses, a group of plants that are separated by at least 400 million years of evolution from vascular plants, were hitherto seen as harbouring an N-glycosylation machinery identical to that of vascular plants. To challenge this view, we have analysed the N-glycomes of several moss species using MALDI-TOF/TOF, PGC-MS/MS and GC-MS. While all species contained the plant-typical heptasaccharide with no, one or two terminal GlcNAc residues (MMXF, MGnXF and GnGnXF, respectively), many species exhibited MS signals with 14.02 Da increments as characteristic for O-methylation. Throughout all analysed moss N-glycans the level of methylation differed strongly even in the same family. In some species, methylated glycans dominated, while others had no methylation at all. GC-MS revealed the main glycan from Funaria hygrometrica to contain 2,6-O-methylated terminal mannose. Some mosses additionally presented very large, likewise methylated complex-type N-glycans. This first finding of methylation of N-glycans in land plants mirrors the presumable phylogenetic relation of mosses to green algae, where O-methylation of mannose and many other monosaccharides is a common trait.

Bryosphere Loss Impairs Litter Decomposition Consistently Across Moss Species, Litter Types, and Micro-Arthropod Abundance

The bryosphere (that is, ground mosses and their associated biota) is a key driver of nutrient and carbon dynamics in many terrestrial ecosystems, in part because it regulates litter decomposition. However, we have a poor understanding of how litter decomposition responds to changes in the bryosphere, including changes in bryosphere cover, moss species, and bryosphere-associated biota. Specifically, the contribution of micro-arthropods to litter decomposition in the bryosphere is unclear. Here, we used a 16-month litterbag field experiment in two boreal forests to investigate bryosphere effects on litter decomposition rates among two moss species (Pleurozium schreberi and Hylocomium splendens), and two litter types (higher-quality Betula pendula litter and lower-quality P. schreberi litter). Additionally, we counted all micro-arthropods in the litterbags and identified them to functional groups. We found that bryosphere removal reduced litter decomposition rates by 28% and micro-arthropod abundance by 29% and led to a colder micro-climate. Litter decomposition rates and micro-arthropod abundance were uncorrelated overall, but were positively correlated in B. pendula litterbags. Bryosphere effects on litter decomposition rates were consistent across moss species, litter types, and micro-arthropod abundances and community compositions. These findings suggest that micro-arthropods play a minor role in litter decomposition in the boreal forest floor, suggesting that other factors (for example, micro-climate, nutrient availability) likely drive the positive effect of the bryosphere on decomposition rates. Our results point to a substantial and consistent impairment of litter decomposition in response to loss of moss cover, which could have important implications for nutrient and carbon cycling in moss-dominated ecosystems.

Desiccation-resurrection linked antioxidant machinery of a moss species Campylopus flexuosus (Hedw.) Bird.

Dehydration and rejuvenation during rehydration is the salient feature of certain plants which can withstand drought. The present study was undertaken to justify the tolerance capacity of Campylopus flexuosus, the moss of the Ponmudi belts of Thiruvananthapuram, against dehydration followed by rehydration. Fresh leafy plants of C. flexuosus were hydrated, afterwards dried, and rehydrated under in vitro environment. In the course of loss of water from cells, the relative water content of desiccated thallus was reduced after 4 h with intense inward curling. Upon rehydration, the RWC was regained 85% of its initial water content within hours. The rehydrated thallus showed the normal morphology. Photosynthetic parameters like chlorophyll b (1.01 to 1.56 μg g –1 ), and total carotenoid (0.251 to 0.514 μg g –1 ) increased remarkably in the desiccated state. Superoxide radical (O2 _) content increased (11.4 nmol/g FW), resulting in an oxidative burst during desiccation. Consequently, antioxidant enzymes such as catalase (0.369 U mg protein −1), superoxide dismutase ( 2.68 to 6.02 Units mg−1), peroxidase ( 0.12 μmol min−1 g−1 protein) and glutathione reductase ( 312 Units mg−1 protein) activities were up-regulated in the desiccated thallus to ameliorate oxidative damage. Increased malondialdehyde (1.08 nmol g−1 FW) content during desiccation substantiates membrane damage and loss of its integrity. During desiccation, the osmolytes sucrose and proline (27.6 and 2.57 μmol/g FW respectively) were enhanced to maintain cell structure integrity. After rehydration, biochemical and morphological properties were maintained similar to hydrated conditions. Thus, the study reflects the unique adaptations of the moss to tide over desiccation tolerance.

Influence of Drought Stress and Rehydration on Moisture and Photosynthetic Physiological Changes in Three Epilithic Moss Species in Areas of Karst Rocky Desertification

The drought resistance mechanism of typical mosses in the karst area was studied, and the water and photosynthetic physiological adaptation of mosses to karst environmental change was analyzed in this paper, which provided the basis for the restoration and control of karst rocky desertification ecological environment. Three superior plants in the rocky desertification area of Guizhou province were selected; they are, respectively, Erythrodontium julaceum (Schwaegr.) Par., Barbula unguiculata Hedw., and Bryum argenteum Hedw. Results show that the three kinds of plant rock mosses of leaf water potential (Ψs), free water content ( V a ), total water content, and relative water content (RWC) decreased; bound water ( V s ), water saturation deficit (WSD), and V s / V a ratio increased; transpiration rate (Tr) fell slightly, under drought stress. The physiological indexes of water have different degrees of recovery after rehydration. The total chlorophyll content shows a trend of first increasing followed by falling and then rising. RWC was negatively related to qN and positively related to F v / F m , yield, ETR, and qP. After rewetting, the fluorescence parameters are returned to average level under mild-to-moderate stress. At the same time, it is hard to get back to the control level under severe pressure. The water use efficiency (WUE) decreased with stress and recovered to different degrees after rehydration.

The Application of Active Biomonitoring with the Use of Mosses to Identify Polycyclic Aromatic Hydrocarbons in an Atmospheric Aerosol

The use of biological indicators of environmental quality is an alternative method of monitoring ecosystem pollution. Various groups of contaminants, including organic ones, can be measured in environmental samples. Polycyclic aromatic hydrocarbons (PAHs) have not yet been determined by the moss bag technique. This technique uses several moss species simultaneously in urban areas to select the best biomonitoring of these compounds, which are dangerous to humans and the environment. In this research, a gas chromatography coupled with mass spectrometry was used for the determination of selected PAHs in three species of mosses: Pleurozium schreberi, Sphagnum fallax and Dicranum polysetum (active biomonitoring) and for comparison using an air filter reference method for atmospheric aerosol monitoring. The chlorophyll fluorescence of photosystem II (PSII) was also measured to assess changes in moss viability during the study. As a result of the study, the selective accumulation of selected PAHs by mosses was found, with Pleurozium schreberi being the best bioindicator—9 out of 13 PAHs compounds were determined in this species. The photosynthetic yield of photosystem (II) decreased by 81% during the exposure time. The relationship between PAHs concentrations in mosses and the total suspended particles (TSP) on the filter indicated the possibility of using this bioindicator to trace PAHs in urban areas and to apply the moss bag technique as a method supporting classical instrumental air monitoring.

Mosses at the bodogol natural conservation education center: species, diversity index, and evenness index

Mosses or Bryophytes are a group of cryptogamous plants or lower plants. Moss can be found in various places that have high humidity by attaching to various substrates, such as soil, rocks and tree bark. PPKA Bodogol is a potential area that protects endemic flora and fauna on the island of Java that has excellent humidity and air for moss growth and supports moss diversity. This study aims to determine the diversity of mosses and their relationship to environmental factors in the PPKA Bodogol. Data collection in this study was carried out at the PPKA Bodogol on 3 routes, namely Cikaweni, Rasamala and Kanopi. This research uses a purposive sampling method with a cover square technique. The results showed that the total number of moss species identified were 21 species. Then it was also known that the highest level of diversity was found on the Rasamala route with a diversity index of 3.03. In the Cikaweni route, was in moderate category, namely 1,967. The lowest diversity index, however, was in the canopy path with a medium category, namely 1.216. Environmental factors such as humidity, temperature, light intensity, and altitude also had an influence on the level of moss diversity of the three routes.

Seasonal Dynamics of Photochemical Performance of PS II of Terrestrial Mosses from Different Elevations

Mosses are critical components of tropical forest ecosystems and have multiple essential ecological functions. The drying and rehydrating and often hot environments in tropical regions present some of the greatest challenges for their photosynthetic activities. There is limited knowledge available on the physiological responses to the changing environments such as temperature and water pattern changes for terrestrial mosses. We examined the seasonal dynamics of photochemical performance of PS II through the measuring of chlorophyll fluorescence of 12 terrestrial mosses in situ from five different elevations by Photosynthesis Yield Analyzer MINI-PAM-II, along with the seasonal changes of climatic factors (air temperature, dew point, relative humidity and rainfall), which were collected by local weather stations and self-deployed mini weather stations. The results showed a great seasonality during observing periods, which, mainly the changes of rainfall and relative humidity pattern, presented significant impacts on the photochemical performance of PS II of terrestrial mosses. All these tested moss species developed a suitable regulated and non-regulated strategy to avoid the detrimental effect of abiotic stresses. We found that only Hypnum plumaeforme, Pterobryopsis crassicaulis and Pogonatum inflexum were well adapted to the changes of habitat temperature and water patterns, even though they still experienced a lower CO2 assimilation efficiency in the drier months. The other nine species were susceptible to seasonality, especially during the months of lower rainfall and relative humidity when moss species were under physiologically reduced PS II efficiency. Anomobryum julaceum, Pogonatum neesii, Sematophyllum subhumile, Pseudotaxiphyllum pohliaecarpum and Leucobryum boninense, and especially Brachythecium buchananii, were sensitive to the changes of water patterns, which enable them as ideal ecological indicators of photosynthetic acclimation to stressed environments as a result of climate change.

Moss phyllid morphology varies systematically with substrate slope

Background and aims – Tracheophyte leaf morphology is well studied but it is unclear if the findings generalize to poikilohydric plants. We tested combinations of hypotheses to determine if microhabitat characteristics, including light exposure, moisture availability, and substrate slope, controlled for morphological differences between upright and prostrate growth forms, affect phyllid surface area and costa length of mosses.Material and methods – We quantified mean phyllid surface-area and costa lengths for four replicates of 38 moss species from Alabama. Phylogenetic comparative methods that model adaptation were used to evaluate the relative evidence for each hypothesis using information criteria. To further explore mechanistic explanations involving substrate slope, we tested whether mosses on vertical substrates differed from those on horizontal substrates in the average amount of water-retaining, nutrient-rich litter they accumulated.Key results – Substrate slope and growth form combined were the best predictors of phyllid surface area. Mosses growing on vertical substrates exhibited smaller phyllid surface area for both growth forms. Although growth form and phyllid length best explained costa length variation, a more complex model including substrate slope performed nearly as well. Within the prostrate growth forms, species growing on vertical substrates exhibit longer relative costa than those on horizontal substrates. We also estimated rapid rates of adaptation for both traits.Conclusion – The smaller phyllid surface area of both upright and prostrate growth forms is possibly an adaptive response to reduced habitat moisture-retention or nutrient quality that vertical substrates offer. The longer costa lengths of prostrate mosses growing on vertical surfaces relative to prostrate mosses on horizontal surfaces, possibly make up for the decreased ability of smaller phyllids to rapidly reabsorb water when it is available. Further work is required to determine if it is truly substrate slope itself that matters or other variables associated with the differences in slope, and to determine how general this phenomenon is.