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At least 19 recordsLinked to original sources
PubMed1978

Cutaneous sporotrichosis in forestry workers. Epidemic due to contaminated Sphagnum moss.

In December 1975 and January and February 1976, an epidemic of cutaneous sporotrichosis occurred in Mississippi among forestry workers and other persons exposed to sphagnum moss used in packing pine seedlings. Seventeen cases were identified, 15 of which were from patients who had been exposed to sphagnum moss from a single source. Attack rates were significantly higher among workers exposed to this moss than among those not exposed. Sporothrix schenckii was cultured from the implicated batch of sphagnum moss but not from other batches. The source of contamination of the sphagnum moss that caused this epidemic and sphagnum moss associated with similar epidemics is unknown. One worker without cutaneous sporotrichosis may have had asymptomatic pulmonary sporotrichosis.

Agricultural Workers' Diseases↗
PubMed2026

Diversification of Cellulose Synthase (CESA) Genes in Mosses Suggests Both Ancient and Recent Gene duplications.

Cellulose is an important polysaccharide that constitutes all plant cell walls, giving them strength and stability. The plant cellulose synthase (CESA) gene family, which encodes the catalytic subunits of cellulose synthesis complexes (CSCs), has diversified independently in several plant lineages, providing an interesting model for understanding selection for gene duplication. Here we quantified the presence of CESA genes across mosses to understand how the process of gene family diversification occurred in this group and how it parallels diversification in other groups. We first examined the CESA gene family in eight species of mosses across seven families for which whole genome assemblies were available. We then identified CESA genes from additional species, for which only short-read sequence data was available, by using BLAST searches and targeted gene assemblies. We validated this approach by comparing the assembled paralogs from the short-read data to the genes identified from whole genome assemblies in the eight reference species. This approach allowed us to identify paralogs directly from short-read data and greatly expand our sample set. Results from the combined empirical data support the hypothesis that CESA genes diversified within the moss lineage at least as early as the mesozoic period, during or possibly even prior to the onset of moss diversification, but also continue to diversify within modern species. In addition, we found evidence for purifying selection as the dominant force shaping these genes and observed that different lineages experienced different levels of evolutionary constraint. Lastly, our approach to assemble paralogs has the potential to allow researchers to improve analyses of gene duplication events.

Physcomitrium patens↗
PubMed2025

New insights into bryophyte arabinogalactan-proteins from a hornwort and a moss model organism.

Two bryophyte models, the hornwort Anthoceros agrestis (Anthoceros) and the moss Physcomitrium patens (Physcomitrium), were analyzed for the presence of arabinogalactan-proteins (AGPs), as the emergence of these signaling glycoproteins in evolution is still under debate. AGPs of both species had a galactan core structure similar to that of other bryophyte and fern AGPs, but different from angiosperm AGPs, as 1,6-linked pyranosidic galactose was almost absent. In the Physcomitrium AGP, furanosidic arabinose (Araf) linkages were mainly terminal (10%) or 5-linked (13%), while in Anthoceros, terminal Araf dominated (26%) and was accompanied by very low amounts of 1,3-Araf and pyranosidic terminal Ara. Unusual 3-O-methylated pyranosidic rhamnose, which has never been detected in cell walls of angiosperms, occurred in both bryophyte AGPs (5% in Anthoceros, 10% in Physcomitrium AGP). This was comparable to AGPs of other spore-producing land plants. A bioinformatic search in the genomes of 14 bryophyte species revealed that most hornworts lack sequences encoding GPI-anchored classical AGPs. Generally, hornworts contained fewer sequences for AGP protein backbones compared with the liverwort Marchantia polymorpha and the moss P. patens. All of them comprise sequences for chimeric AGPs, and among those, surprisingly xylogen-like AGPs. Homologous sequences encoding glycosyltransferases and other enzymes involved in the synthesis and decoration of the AGP galactan framework were present in all bryophyte genomes. Immunocytochemistry of Anthoceros tissue detected AGPs at the plasma membrane/cell wall interface but also at the tonoplast, suggesting new functions of AGPs in bryophytes.

Mucoproteins↗
PubMed1977

Synthesis and function of 9,12,15-octadecatrien-6-ynoic acid in the moss ceratodon purpureus.

Biosynthesis of all-cis-9,12,15-octadecatrien-6-ynoic acid in the moss, Ceratodon purpureus, was studied using protonemata cultures with labeled 9,12,15-octadecatrienoic (linolenic) and 6,9,12,15-octadecatetraenoic acids as substrates. Both acids were efficiently converted into the acetylenic and into 5,8,11,14,17-eicosapentaenoic acids. Accordingly, the introduction of a triple bond in position 6 of linolenic acid involves formation of a double bond as a discrete step. Acetylenic acid triglycerides are reserve lipids in the moss. Under suitable growth conditions the acetylenic acids are catabolized and partly reused via acetate for de novo synthesis of fatty acids. They are not used for more direct syntheses of the common polyunsaturated fatty acids.

Fatty Acids↗
PubMed1976

The conservation of poly-A-containing RNA during the dormant state of the moss Polytrichum commune.

The moss Polytrichum commune can be dried to less than 2% of free water and kept for some weeks without losing its viability. Upon rehydration of the moss, protein synthesis starts about 60 minutes before incorporation of radioactive precursors into RNA can be observed. Pulse labeled total RNA and poly-A-containing RNA do not show quantitative or qualitative alterations during desiccation up to 20 days.

Drug Stability↗
PubMed2025

Phosphoproteomics analysis provides novel insight into the mechanisms of extreme desiccation tolerance of the desert moss Syntrichia caninervis.

Syntrichia caninervis is a model species for research on desiccation tolerance (DT) because it is capable of rapidly responding to drastic changes in water conditions. Phosphorylation, a key post-translational modification process that is rapid and reversible, enables the rapid regulation of protein functions, aiding plants to quickly adapt to changing environments. Modifications to phosphorylation may play a crucial role in the DT of S. caninervis, although no studies have been published. Here, we report a 4D label-free high-resolution dynamic proteomic and phosphoproteomic analysis of S. caninervis during dehydration and rehydration, allowing for the quantification of 2854 proteins and 1177 phosphoproteins, including 1447 differentially expressed proteins (DEPs) and 699 differentially phosphorylated proteins (DPPs). Among the phosphoproteins, 36.5% displayed changes in protein abundance. The proteomic and phosphoproteomic changes involved proteins (DEPs and DPPs) that were mainly involved in photosynthesis, glutathione metabolism, the citrate cycle, and the biosynthesis of secondary metabolism pathways during dehydration. During rehydration, DEPs and DPPs were mainly associated with processes related to ribosome and energy metabolism. In summary, during dehydration, phosphorylation mainly regulates signal transduction and metabolic processes, allowing plants to adapt to a loss of water. During rehydration, phosphorylation controls repair and recovery mechanisms, restoring metabolic activity and reestablishing cellular functions. ScDHAR1, a protein involved in glutathione metabolism, was differentially phosphorylated at two serine sites (S29 and S218) in response to desiccation. Further analysis revealed that phosphorylation of S29/S218 in ScDHAR1 significantly increased its enzymatic activity, thereby enhancing the DT of S. caninervis in situ. This work establishes a phosphoprotein database for a DT moss. These findings not only broaden our understanding of S. caninervis DT but also fill knowledge gaps in the field of phosphoproteomics in DT mosses, while providing valuable data resources for future related research.

Phosphoproteins↗
PubMed2025

TRB proteins in moss reveal their evolutionarily conserved roles in plant development and telomere maintenance.

Telomere repeat binding (TRB) proteins are plant-specific proteins with a unique domain structure distinct from telomerebinding proteins in animals and yeast. While extensively studied in seed plants, their role in early-diverging plant lineages remains largely unexplored. Here, we investigate TRB proteins in a model moss, Physcomitrium patens, to assess their evolutionary conservation and functional significance. Functional analysis using single knockout mutants revealed that individual PpTRB genes are essential for normal development, with mutants exhibiting defects in the two-dimensional (protonemal) stage, and more prominently, in the formation of three-dimensional (gametophore) structures. Some double mutants displayed telomere shortening, a phenotype also observed in TRB-deficient seed plants, indicating a conserved role for TRBs in telomere maintenance. Transcriptome profiling of TRB mutants revealed altered expression of genes associated with transcriptional regulation and stimulus response in protonema. Subcellular localization studies across various plant cell types confirmed that PpTRBs, like their seed plant counterparts, localize prevalently to the plant nucleus and mutually interact. In bryophytes, TRBs form a monophyletic group that mirrors the species phylogeny, whereas in seed plants, TRBs have diversified into two distinct monophyletic groups. Our findings provide the first comprehensive characterization of TRB proteins in non-vascular plants and demonstrate their conserved roles in telomere maintenance, with additional implications for plant development and gene regulation across land plant lineages.

Bryopsida↗
PubMed2026

Insights into the regulatory roles of LIKE-HETEROCHROMATIN PROTEIN 1 and its targeting to different nuclear compartments modulated by NLS and the conserved domains in the moss Physcomitrium patens.

LIKE-HETEROCHROMATIN PROTEIN 1 (LHP1) is a polycomb group protein that exists in shared multiprotein complexes that harbor core PRC1 and PRC2 proteins. We previously characterized LHP1 in the moss Physcomitrium patens and showed that its function is closely linked with regulation of RNA metabolic processes and the protein is distributed in the nucleoplasm, subnuclear foci, and the nucleolus. To gain mechanistic insight into PpLHP1-mediated gene regulation, in the present study genome-wide changes in transcript profiles of genes affected by loss-of-PpLHP1 function were studied using pplhp1 mutants. RNA-seq analysis reveals a key role for PpLHP1 in regulating energy metabolic processes, ribosome-related pathways, stress signaling/responsive pathways, DNA transcription, etc. ChIP using H3K27me3 coupled with qRT-PCR shows that PpLHP1 suppresses transcription at 5S rRNA promoters and the untimely activation of genes regulating developmental transition by PRC2-dependent and independent mechanisms. To study how PpLHP1 finds its targets in different nuclear compartments and the roles of the multiple NLSs and the conserved domains in guiding the protein, FRAP and deletion studies were performed. These show that PpLHP1 is a mobile protein that diffuses freely in the nucleoplasmic space showing different retention times in the nucleolus, nucleoplasm, and the subnuclear foci indicating its differential affinity for targets at these sites. Expression of PpLHP1 fragments in protonema cells and its subsequent visualization under confocal microscope shows that localization of PpLHP1 to different subnuclear compartments is guided by the monopartite NLS2, CD, and CSD that also play a key role in promoting subnuclear foci formation in the nucleoplasm.

Bryopsida↗
PubMed2026

The R2R3-MYB transcription factor ScMYB20 negatively regulates drought and salt tolerance through a dual-repression of ScCHALCONE SYNTHASE-1 (ScCHS1)-mediated flavonoid biosynthesis in the desert moss Syntrichia caninervis.

The desert moss Syntrichia caninervis is one of the most desiccation-tolerant land plants known and provides a powerful system for dissecting the molecular foundations of extreme stress adaptation in early-diverging land lineages. The MYB transcription factor superfamily orchestrates secondary metabolism and stress signaling across plants, yet its lineage-specific evolution and mechanistic deployment in bryophytes remain poorly understood. Here, we identified 65 ScMYB genes in the S. caninervis genome and showed that the family expanded predominantly through dispersed duplication, with no detectable synteny to vascular-plant MYBs, indicating bryophyte-specific neo-functionalization. Integrating phylogenetic clustering, cis-element architecture and stress-responsive expression profiling, we pinpointed ScMYB20, a nuclear-localized, S13-subgroup R2R3-MYB that is rapidly and strongly induced by dehydration and salinity. Heterologous overexpression in Arabidopsis, together with overexpression and RNAi in S. caninervis, demonstrated that ScMYB20 negatively regulates drought and salt tolerance by suppressing antioxidant capacity, osmotic adjustment and photosynthetic performance, while concomitantly elevating ROS and MDA accumulation. Mechanistically, ScMYB20 directly binds a TAACCA motif in the ScCHS1 promoter to repress its transcription, and simultaneously sequesters the WD40 protein ScTTG1, a positive transcriptional activator of ScCHS1, thereby antagonising ScTTG1-mediated activation. Transient ScCHS1 overexpression restored flavonoid accumulation, antioxidant capacity and stress tolerance. Together, our findings define a dual-repression module (ScMYB20-ScTTG1-ScCHS1) that fine-tunes flavonoid flux under abiotic stress, and provide evolutionary and mechanistic insights into how R2R3-MYB repressors evolved to balance metabolic investment and stress survival in land plants.

Syntrichia caninervis↗
PubMed2025

STEMIN transcription factor drives selective chromatin remodeling for gene activation within a relaxed chromatin during reprogramming in the moss Physcomitrium patens.

Land plants exhibit remarkable cellular plasticity, readily reprogramming differentiated cells into stem cells in response to internal and external stimuli. While chromatin remodeling is crucial for cellular reprogramming, its interplay with gene expression during reprogramming into stem cells remains elusive. In the moss Physcomitrium patens, wounding induces reprogramming of leaf cells facing wounded cells to change into chloronema apical stem cells through the activation of the AP2/ERF transcription factor STEMIN. In this study, we employed multimodal single-nuclei RNA and ATAC sequencing to explore the interplay between gene expression and chromatin dynamics during STEMIN-mediated reprogramming. Profiling 20 883 single-nuclei from gametophores, protonemata, and cut leaves, we identified 11 distinct cell types including reprogramming leaf cells. Our analysis revealed that reprogramming leaf cells exhibit a partly relaxed chromatin landscape and STEMIN transcription factors selectively enhance accessibility at specific genomic loci essential for stem cell formation. Thus, our results indicate that wounding initiates a broad chromatin relaxation, creating a permissive environment and specific transcription factors act to refine this permissive state by specifically relaxing chromatin regions critical for reprogramming.

Bryopsida↗
PubMed1977

A reply to "Validity and student acceptance of a graphoanalytic approach to personality" by Vestewig, Santee, and Moss.

Vestewig, Santee, and Moss have interpreted their 1976 study of graphoanalysis as wholly offensive to the validity of this system of personality assessment. But re-examination of their data reveals that some findings actually support the validity of graphoanalysis in spite of the fact that their methodology stacked the cards against the handwriting experts. Suggestions are made as to how this study could have been made comparable to those studies which show validity of handwriting analysis by the "global" or "holistic" method, and it is noted that under these conditions the results might have been quite different.

Evaluation Studies as Topic↗
PubMed1978

[The behaviour of mycobacterium intracellulare serotyp Davis and mycobacterium avium in the head region of sphagnum moss vegetation after experimental inoculation (author's transl)].

After the inoculation in the head region of sphagnum moss vegetation (Sph. magellancium-Erica Association and Sph. apiculatum-Eriophorum angustifolium Ass.) reach the mycobacteria the hyaline cells of Sphagnum (Fig. 1). The count of M. intracellulare serotyp Davis decreases rapidly already in three days after the inoculation of Sph. magellanicum Ass. and this trend in the course of incubation is being continued. In 27 days following the inoculation only 2 of 7 specimens contained a small amount of this mycobacteria (Tab. 2, Fig. 2). In the head region of Sph. apiculatum Ass. the mycobacterial count was more rapidly going down. Already 13 days after the inoculation only 2 of 7 specimens were found mycobacteria-positive; 24 days after the inoculation no mycobacteria were present (Tab. 3, Fig. 3). The elimination of M. avium from the head region of Sph. magellanicum Ass. follows within 13 days after the inoculation (Tab. 4, Fig. 4). For the microbial growth well predisponated hyaline cells with their porous cell wall and hollow spaces possess probably a mechanism, which is effective against microbial contamination of the productive head region of Sphagnum vegetation. Our further investigations have shown, that the growth of mycobacteria follows in the deeper, partially decomposed region of Sphagnum vegetation (KAZDA, 1978).

Mycobacterium↗
PubMed2025

Moss BRCA2 lacking the canonical DNA-binding domain promotes homologous recombination and binds to DNA.

BRCA2 is crucial for mediating homology-directed DNA repair (HDR) through its binding to single-stranded DNA (ssDNA) and the recombinases RAD51 and DMC1. Most BRCA2 orthologs have a canonical DNA-binding domain (DBD) with the exception of Drosophila melanogaster. It remains unclear whether such a noncanonical BRCA2 variant without DBD possesses a DNA-binding activity. Here, we identify a new noncanonical BRCA2 in the model plant Physcomitrium patens (PpBRCA2). We establish that PpBRCA2 is essential for genome integrity maintenance, somatic DNA double-strand break (DSB) repair, HDR-mediated gene targeting, and RAD51 foci recruitment at DNA break sites. PpBRCA2 is also critical for DSB repair during meiosis. Interestingly, PpBRCA2 interacts strongly with RAD51 but weakly with DMC1, suggesting a distinct meiotic function compared to other BRCA2 homologs. Despite lacking the canonical DBD, PpBRCA2 binds ssDNA through its disordered N-terminal region and efficiently promotes HDR. Our work highlights that the ssDNA binding capacity of BRCA2 homologs is conserved regardless of the presence of a canonical DBD and provides a deeper understanding of BRCA2's functional diversity across species.

BRCA2 Protein↗