Scopelophila Cataractae Research Articles

The role of mosses in 'clean and green' phytoremediation technology: a review paper.

Phytoremediation, the practice of removing heavy metals from contaminated sites using plants, has emerged as a cost-effective, environmentally friendly green technology to restore damaged ecosystems. Mosses, in particular, demonstrate high phytoremediation potential due to their ability to accumulate heavy metals such as lead, zinc, copper, chromium, cadmium, and iron from contaminated soil and water. This review systematically examines 37 research articles published from 2000 to 2022, focusing on the on the use of mosses for phytoremediation. Moss species, such as Funaria hygrometrica Hedw, Scopelophila cataractae (Mitten) Brotherus, Dicranum scoparium Hedw, Dicranum polysetum Sw. ex anon, Hypnum cupressiforme Hedw, Physcomitrium cyathicarpum Mitt, Barbula constricta Mitt, and Leptodictyum riparium (Hedw.) Warnst. have been identified as ideal candidates for phytoremediation efforts. Specific species of mosses, such as Dicranum species, are noted for their excellent bioaccumulation capabilities of elements like vanadium, manganese, and rubidium, serving as indicators of air pollution. Additionally, Hypnum cupressiforme has proven to be a reliable indicator of sulfur dioxide in natural and anthropogenic sources. This comprehensive review highlights the significant phytoremediation potential of mosses, emphasizing their role as valuable bioaccumulators and indicators of heavy metals and pollutants. The findings highlight the necessity of further research to enhance the application of mosses in environmental management and remediation strategies, ultimately contributing to the development of sustainable and effective solutions for pollution control.

Effects of copper accumulation on growth and development of Scopelophila cataractae grown in vitro

Scopelophila cataractae was cultured in vitro for 16 weeks to assess the contrasting effects of Cu on growth and reproduction, as well as gametophore stage. To induce buds and gametophores of S. cataractae, ten treatments (tr 1 to tr 10) of culture media were prepared using a combination of mineral salts, sugar, vitamin B complex, CuSO4, and exogenous hormones. Highest numbers of gametophores and buds were formed in media containing 500 µM CuSO4 in co-application with auxin and cytokinin, as shown in the modest Cu treatments (tr 6 and tr 7, 26 per cushion and 255 per 25 mm2, respectively). A 5000 µM CuSO4 concentration inhibited development of protonema, possibly due to Cu toxicity, resulting in chloronema forming contorted filaments or short cells containing lipid bodies, and brood body diaspores but no gametophore or bud formation. In this study, S. cataractae Cu accumulation in tissue was substantial (up to 2843.1 mg kg-1; tr 6) with no or minimal adverse effects, reflecting its potential for phytoremediation of Cu in terrestrial and aquatic ecosystems. The highest atomic percentages of Cu and Zn were detected in the stem surfaces of gametophores treated with 500 µM CuSO4 (11% atomic Cu and 7% atomic Zn), which served as a primary heavy metal storage site, ultimately protecting cells from metal toxicity. The success of this in vitro study on S. cataractae should also aid ex situ conservation efforts for a variety of rare moss taxa in the wild.

Molecular basis of intraspecific differentiation for heavy metal tolerance in the copper moss Scopelophila cataractae

The remarkable capacity of bryophytes to tolerate extremely challenging abiotic conditions allows us to enhance our understanding of the diversity of molecular mechanisms involved in plant stress response. Here, we used next generation sequencing to study DNA methylation and gene expression changes in plants from four populations of the metallophyte moss Scopelophila cataractae experimentally exposed to either Cd or Cu. These populations previously showed differences in tolerance to both metals, so here, we aimed to investigate the molecular basis of this phenotypic differentiation. We found no evidence of genetic differentiation among the populations studied. The epigenetic data, however, showed limited but significant population-specific changes in DNA methylation in response to both metals. Exposure to acute Cu stress in the laboratory led to the downregulation of genes involved in heavy metal tolerance in both the more and the less tolerant populations, but this response was quantitatively higher in the most tolerant. We propose that chronic exposure to varying levels of heavy metals in the field led to potentially non-genetically-based intraspecific differentiation for heavy metal tolerance in S. cataractae . The most tolerant plants invested more in constitutive protection and were more efficient at entering a conservative state when faced with acute Cu stress. • We study the molecular mechanisms driving differences in metal tolerance in a moss. • Genetic differentiation did not explain intraspecific differences in tolerance. • We found population-specific epigenetic changes in response to metals. • The most tolerant plants invested more in constitutive molecular protection. • They were more efficient in entering an energy conservative state under acute stress.

Heavy Metal Accumulation and Copper Localization in Scopelophila cataractae in Thailand

Four specimens of gametophores and protonemata of Scopelophila cataractae (copper moss) were collected from a stream in Doi Suthep-Pui National Park, Thailand in order to determine heavy metal accumulation and Cu localization. The order of total metal concentrations in the protonemata and leaf cell surfaces of S. cataractae was Fe > Zn > Cu. Significant Cu values (> 400mg kg-1) were found in both gametophores and protonemata. Growth substrates were considered as a key source of heavy metals in the sampling stream. X-ray spectrometry (EDS micro-analyser) detected the localization of ten elements (C, O, Mg, Al, Si, Ca, S, Cu, Zn and In); substantial atomic percentages of Al, Cu and Zn were noted in leaf surfaces and protonemata. These metallic elements were found in highest proportion. To some extent, cell surfaces at the basal leaf costa showed the highest peak value compared to medial and apical leaf portions (≈ 4.3 at.%). This Cu moss can be used as a bioindicator to reflect anthropogenic activities in stream ecosystems.

Patterns and mechanisms of heavy metal accumulation and tolerance in two terrestrial moss species with contrasting habitat specialization

Anthropogenic activities have increased exposure to heavy metal pollution in previously uncontaminated ecosystems, threatening plant communities. Considering that phenotypic variation underlies rapid adjustment to challenging environmental conditions in natural populations, the study of variation in traits related to plant response to heavy metal stress provides valuable insight into the likelihood of a population’s survival. This paper investigates patterns of intraspecific phenotypic variation for heavy metal accumulation and tolerance in bryophytes, one of the most resilient and relatively understudied plant taxa. We examined two moss species with contrasting affinities for heavy metals: the heavy metal specialist Scopelophila cataractae, and the facultative metallophyte Ceratodon purpureus. We sampled four populations of S. cataractae in close microhabitats with different contamination levels of Cd and Cu, one population of C. purpureus in an urban area, and separate lab-maintained male and female isolates from one population of C. purpureus growing in axenic conditions. After clonally propagating all populations under control, Cd and Cu treatments, we measured plant fitness, oxidative damage, and Cd and Cu accumulation. Scopelophila cataractae isolates from microhabitats with higher levels of metals in the field (Sc2, Sc3) were more tolerant than those collected in less contaminated microhabitats (Sc1, Sc4). Sc2 and Sc3 accumulated significantly less Cu in the leaves compared to the stem which could limit damage to their main photosynthetic organs and contribute to the observed differences in Cu tolerance. In contrast C. purpureus showed intraspecific differences in tolerance to Cd and Cu, but not in accumulation. These differences arose among isolates that had never been exposed to heavy metals before. We also report the first evidence for sexual dimorphism for Cd tolerance in this species, with females being more tolerant than males. Altogether, our results provide novel insights into the mechanisms used by bryophytes to deal with heavy metal stress, as well as the first evidence for metal-dependent, sex-specific differences in heavy metal tolerance in bryophytes.

Copper Content and Resistance Mechanisms in the Terrestrial Moss Ptychostomum capillare: A Case Study in an Abandoned Copper Mine in Central Spain.

We present a case study on the tissue absorption of copper of a widely distributed moss species, Ptychostomum capillare in the polluted soil of an abandoned copper mine in central Spain. We studied the soil properties in a copper soil pollution gradient and sampled the moss tufts growing on them in four plots with contrasted soil copper levels. We determined the copper content in the soil and in the moss tissues. On these moss samples, we also performed histochemical tests and X-ray dispersive spectrometry coupled with scanning electron microscopy (SEM-EDX), both in untreated shoots and in samples where surface waxes were removed. We checked the behavior of this species using a metallophillous moss, Scopelophila cataractae, for comparative purposes. Copper contents in P. capillare seem to depend more on available, rather than total soil copper contents. Our results indicate that this moss is able to concentrate 12-fold the available soil copper in soil with low available copper content, whereas in the most polluted soil the concentration of Cu in the moss was only half those levels. Both histochemical and SEM-EDX tests show no surface copper in the mosses from the least polluted plot, whereas in samples from the soil with highest copper content, the removal of surface waxes also reduces or removes copper from the moss shoots. Our observations point at a mixed strategy in P. capillare in this copper mine, with metal accumulation behavior in the lowest Cu plot, and an exclusion mechanism involving wax-like substances acting as a barrier in the most polluted plots. These distortions impede the estimation of environmental levels and thus compromise the value of this moss in biomonitoring. We highlight the need of extending these studies to other moss species, especially those used in biomonitoring programs.

<p><strong>Bryoflora Salvadorensis 3. An updated checklist and new records of Pottiaceae for El Salvador</strong></p>

An updated list of the taxa of the moss family Pottiaceae recorded for El Salvador is presented, based on literature reports and own investigations. At present, 20 genera of Pottiaceae are known from El Salvador, of which four (Barbula, Scopelophila, Trichostomum, Weissia) are reported as new for the country. Eight species and two varieties are reported as new for El Salvador: Barbula orizabensis, Bryoerythrophyllum ferruginascens, B. inaequalifolium, Chionoloma tenuirostre, Didymodon acutus var. icmadophilus, Hyophila nymaniana, Leptodontium viticulosoides var. viticulosoides, Scopelophila cataractae, Trichostomum brachydontium, and Weissia jamaicensis, increasing the total number of species to 35. Information on the distribution, main substrate types, and approximate elevational range in Mesoamerica as well as the general distribution are provided for all taxa.

Effects of copper ions on the growth and photosynthetic activity of Scopelophila cataractae

Scopelophila cataractae is a rare species that grows in environments with high concentration of copper. We analyzed the relationship between plant growth and copper ion concentration in the rainwater in a field study and the relationship between photosynthetic activity and copper ion concentration in a laboratory. We surveyed six sites with S. cataractae; these sites had rainwater copper ion concentrations ranging from 16.8 to 29.2 ppm. We found that the growth area, gametophore size, and leaf size of S. cataractae decreased as copper ion concentration increased. We observed reduced photosynthetic activity at copper ion concentrations of 20.0 ppm or higher. We discovered that the growth of S. cataractae gametophores was adversely affected by copper ions at concentrations commonly observed under copper roofs. Thus, S. cataractae may inhabit areas with high concentrations of copper ion (∼30 ppm) partly because of a selective advantage when interspecific competition is high. We recommend that copper roofs should be renewed partly rather than all at once, as aged copper roofs create environments with copper ion concentrations suitable for S. cataractae.

The 2016 Crum Workshop: Bryophytes of the Red River Gorge Geological Area, Kentucky

We inventoried bryophytes in Kentucky's Red River Gorge region (RRG) during the 4-day 2016 Crum Moss Workshop and compared our findings with those of Studlar and Snider (1989), which were based primarily on collections by Studlar 40 years earlier. We collected 185 bryophyte species (140 mosses and 45 liverworts), mainly around Corbin sandstone cliffs, arches, and rockhouses (overhangs). About 61% of the 260 taxa (176 mosses and 84 hepatics, using updated nomenclature) reported in 1989 were found again. We added to the RRG flora 20 species (15 mosses and 5 liverworts), including the disjunct Heterocladium macounii and 5 state records: 2 mosses (Serpoleskea minutissima and Cryphaea nervosa) and 3 liverworts (Microlejeunea globosa, Frullania virginica, and Cheilolejeunea conchifolia). Four species characteristic of rockhouses in sandstone gorges were recollected: Bryoxiphium norvegicum, Hookeria acutifolia, Diphyscium mucronifolium (formerly D. cumberlandianum), and Syrrhopodon texanus. The globally rare “copper moss”, Scopelophila cataractae was found again and with a sporophyte, a first report for North America. A total (including literature reports) of 289 bryophyte species (200 moss and 89 liverworts) are now known from the RRG.

EVALUATION OF METAL CONTAMINATION FOR RIVER USING BRYOPHYTE IN THE KINOKAWA RIVER CATCHMENT

Metal concentration of river water is not always useful for evaluating metal contamination in a catchment because metal concentration of river water is neither always high nor uniform. Therefore, we studied the evaluation of river metal contamination using the metal concentration of bryophyte. Metal concentrations of bryophyte sampled in both the lower stream of the closed Cu mine (120 to 26,000, 25 to 2,400 and 50 to 190 mg/kg-dry for Cu, Co and Ni) and the serpentinite (24 to 59 and 58 to 650 mg/kg-dry for Co and Ni) were higher than background metal concentrations of bryophyte (2 to 96, 2 to 20 and 2 to 43 mg/kg-dry for Cu, Co and Ni). Therefore, it was thought that metal concentrations of bryophyte sampled in the lower stream of the closed Cu mine (Cu, Co and Ni) and the serpentinite (Co and Ni) were affected by the closed Cu mine and the serpentinte, respectively. A kind of hyper accumulator bryophyte similar Scopelophila cataractae was often found around the closed Cu mine and was found around the serpentinite. Its metal concentration was high (1,100 to 26,000, 33 to 2,400 and 81 to 650 mg/kg-dry for Cu, Co and Ni). Metal concentrations of another hyper accumulator bryophyte similar Scopelophila cataractae had high and a wide range of metal concentrations (2 to 5,900, 2 to 150 and 2 to 590 mg/kg-dry for Cu, Co and Ni). Therefore, those of hyper accumulator bryophyte were thought to be useful for a Cu, Co and Ni contamination indicator.

Scopelophila cataractae (Mitt.) Broth. found in Nagano Prefecture, Japan

Scopelophila cataractae (Mitt.) Broth. found in Nagano Prefecture, Japan

Efficient and Heritable Targeted Mutagenesis in Mosses Using the CRISPR/Cas9 System.

Targeted genome modification by RNA-guided nucleases derived from the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9) system has seen rapid development in many organisms, including several plant species. In the present study, we succeeded in introducing the CRISPR/Cas9 system into the non-model organism Scopelophila cataractae, a moss that exhibits heavy metal tolerance, and the model organism Physcomitrella patens Utilizing the process by which moss plants regenerate from protoplasts, we conducted targeted mutagenesis by expression of single-chain guide RNA (sgRNA) and Cas9 in protoplasts. Using this method, the acquisition rate of strains exhibiting phenotypic changes associated with the target genes was approximately 45-69%, and strains with phenotypic changes exhibited various insertion and deletion mutations. In addition, we report that our method is capable of multiplex targeted mutagenesis (two independent genes) and also permits the efficient introduction of large deletions (∼3 kbp). These results demonstrate that the CRISPR/Cas9 system can be used to accelerate investigations of bryology and land plant evolution.

Accumulation of Arsenic and Copper by Bryophytes Growing in an Aquatic Environment near Copper Mine Tailings

Bryophytes with high As accumulation affinity were identified in the aquatic environment. We surveyed a stream near copper mine tailings and then conducted laboratory experiments to confirm As accumulation in the bryophytes with high As affinity. We found that a moss, Scopelophila cataractae, accumulates As in addition to Cu in aquatic environments and confirmed it in laboratory experiments. The highest value for As in S. cataractae from the field survey was 1300 mg/kg dry weight at relatively low As concentrations in the stream water (0.005 mg/L). In addition, Brachythecium plumosum and Rhynchostegium riparioides may also be useful bryophytes for accumulation of Cu and As, though the mechanisms of As accumulation might differ between these two bryophytes and S. cataractae.

Copper mediates auxin signalling to control cell differentiation in the copper moss Scopelophila cataractae.

The copper (Cu) moss Scopelophila cataractae (Mitt.) Broth. is often found in Cu-enriched environments, but it cannot flourish under normal conditions in nature. Excess Cu is toxic to almost all plants, and therefore how this moss species thrives in regions with high Cu concentration remains unknown. In this study, we investigated the effect of Cu on gemma germination and protonemal development in S. cataractae. A high concentration of Cu (up to 800 µM) did not affect gemma germination. In the protonemal stage, a low concentration of Cu promoted protonemal gemma formation, which is the main strategy adopted by S. cataractae to expand its habitat to new locations. Cu-rich conditions promoted auxin accumulation and induced differentiation of chloronema into caulonema cells, whereas it repressed protonemal gemma formation. Under low-Cu conditions, auxin treatment mimicked the effects of high-Cu conditions. Furthermore, Cu-induced caulonema differentiation was severely inhibited in the presence of the auxin antagonist α-(phenylethyl-2-one)-indole-3-acetic acid, or the auxin biosynthesis inhibitor l-kynurenine. These results suggest that S. cataractae flourishes in Cu-rich environments via auxin-regulated cell differentiation. The copper moss might have acquired this mechanism during the evolutionary process to benefit from its advantageous Cu-tolerance ability.

Effect of copper stress on cup lichens Cladonia humilis and C. subconistea growing on copper-hyperaccumulating moss Scopelophila cataractae at copper-polluted sites in Japan

We investigated lichen species in the habitats of the copper (Cu)-hyperaccumulating moss Scopelophila cataractae and found that the cup lichens Cladonia subconistea and C. humilis grow on this moss. We performed X-ray fluorescence and inductively coupled plasma mass (ICP-MS) analysis of lichen samples and measured the visible absorption spectra of the pigments extracted from the samples to assess the effect of Cu stress on the cup lichens. The chlorophyll a/b ratio and degradation of chlorophyll a to pheophytin a were calculated from the spectral data. X-ray fluorescence analysis indicated that Cu concentrations in cup lichens growing on S. cataractae were much higher than those in control samples growing on non-polluted soil. Moreover, Cu microanalysis showed that Cu concentrations in parts of podetia of C. subconistea growing on S. cataractae increased as the substrate (S. cataractae) was approached, whereas those of C. humilis growing on S. cataractae decreased as the substrate was approached. This reflects the difference in the route of Cu ions from the source to the podetia. Furthermore, ICP-MS analysis confirmed that C. subconistea growing on S. cataractae was heavily contaminated with Cu, indicating that this lichen is Cu tolerant. We found a significant difference between the visible absorption spectra of pigments extracted from the Cu-contaminated and control samples. Hence, the spectra could be used to determine whether a cup lichen is contaminated with Cu. Chlorophyll analysis showed that cup lichens growing on S. cataractae were affected by Cu stress. However, it also suggested that the areas of dead moss under cup lichens were a suitable substrate for the growth of the lichen. Moreover, it suggested that cup lichens had allolepathic effects on S. cataractae; it is likely that secondary metabolites produced by cup lichens inhibited moss growth.

Spectral properties of the Cu-hyperaccumulating moss Scopelophilacataractae

To determine the characteristics of a Cu-hyperaccumulating moss Scopelophila cataractae and the influence of Cu on its structure and on chlorophyll (Chl), we measured reflectance and fluorescence (FL) spectra of S. cataractae samples with different Cu concentrations before and after wetting and the absorption spectra of Chl extracted from these samples. We found relationships between the spectral properties and Cu concentration. These relationships can be explained as follows. The higher the Cu concentration is, the lower is the plasticity of the cell wall, and the smaller is the increase in illuminated area due to the opening of the leaves after wetting. This results in a smaller increase in absorption and smaller decrease in reabsorption of the FL by Chl itself, and accordingly, a smaller increase in the FL band of Chl after wetting. Moreover, we found that the Chl concentration in S. cataractae is much higher than that in other common mosses and is correlated with an increase in the FL band of Chl after wetting. The remarkable increase in FL seen in S. cataractae and the slight increase in FL observed in other common mosses after wetting can be explained based on these findings.

Regulation of gemma formation in the copper moss Scopelophila cataractae by environmental copper concentrations

Considerable attention has recently been focused on the use of hyperaccumulator plants for the phytoremediation of soils contaminated with heavy metals. The moss, Scopelophila cataractae (Mitt.) Broth., is a typical hyperaccumulator that is usually observed only in copper-rich environments and which accumulates high concentrations of copper in its tissues. However, many of the physiological processes and mechanisms for metal hyperaccumulation in S. cataractae remain unknown. To address this issue, we examined the mechanisms regulating gemma formation, which is considered the main strategy by which S. cataractae relocates to new copper-rich areas. From this study we found that treatment of S. cataractae with high concentrations of copper suppressed gemma formation but promoted protonemal growth. The suppressive effect was not observed by treatment with heavy metals other than copper. These results suggest the importance of copper-sensitive asexual reproduction in the unique life strategy of the copper moss, S. cataractae.

<p><strong><em>Scopelophila cataractae</em> found growing on tree trunks in northern Thailand</strong></p>

Scopelophila cataractae is here reported from Thailand, where it occurs on the trunks of an emergent tree in an evergreen montane forest.

Metal-tolerant moss Scopelophila cataractae accumulates copper in the cell wall pectin of the protonema

The growth kinetics in the presence of copper (Cu) of the protonema of the moss Scopelophila cataractae and the matrix polysaccharides of its cell walls have been analyzed in this study. Protonemal cells cultured in a medium containing 0.2 mM CuSO 4 showed a rapid accumulation of Cu, reaching a maximum between 30 and 60 d at approximately 65 μmol g −1 DW. Uronic acids were found in similar amounts in cell walls of both control and Cu-treated cells, whereas arabinose and galactose decreased to 61–67% in the presence of Cu. Cell wall polysaccharides were determined after successive extraction with 50 mM CDTA, 50 mM Na 2CO 3, 1 M KOH, and 4 M KOH. The pectic fractions (CDTA- and Na 2CO 3-soluble) decreased to 47% and the hemicellulosic fractions (1 M KOH- and 4 M KOH-soluble) to 86% under Cu application. Approximately 43% of the Cu taken into cell walls was released following endo-pectate lyase treatment, suggesting that two-fifths of the total Cu accumulation was tightly bound to the homogalacturonan of the cell wall pectin.

A novel α-glucosidase from copper-tolerant moss Scopelophila cataractae

A novel α-glucosidase from copper-tolerant moss Scopelophila cataractae