The study reveals that in the liverwort Marchantia polymorpha, the UV‑B photoreceptor MpUVR8 forms homodimers that monomerize and accumulate in the nucleus upon UV‑B exposure, activating COP1‑dependent growth inhibition, gene expression reprogramming, and UV‑absorbing metabolite production. MpRUP promotes redimerization of MpUVR8, acting as a negative regulator, while MpSPA also negatively modulates UVR8 signaling, indicating lineage‑specific diversification of UV‑B signaling components that originated over 400 Myr ago.
The study sequenced genomes of ericoid mycorrhiza‑forming liverworts and experimentally reconstituted the symbiosis, revealing a nutrient‑regulated state that supports intracellular colonization. Comparative transcriptomics identified an ancestral gene module governing intracellular symbiosis, and functional validation in Marchantia paleacea through genetic manipulation, phylogenetics, and transactivation assays confirmed its essential role. The findings suggest plants have retained and independently recruited this ancestral module for diverse intracellular symbioses.
The study investigates the role of the chromatin regulator MpSWI3, a core subunit of the SWI/SNF complex, in the liverwort Marchantia polymorpha. A promoter mutation disrupts male gametangiophore development and spermiogenesis, causing enhanced vegetative propagation, and transcriptomic analysis reveals that MpSWI3 regulates genes controlling reproductive initiation, sperm function, and asexual reproduction, highlighting its ancient epigenetic role in balancing vegetative and reproductive phases.
The study investigates the role of two ATP-binding cassette transporters, MpABCG1 and MpABCG36, in the sequestration of specialized metabolites within oil bodies of the liverwort Marchantia polymorpha. Loss‑of‑function mutants displayed reduced accumulation of sesquiterpenes and, specifically for MpABCG1, decreased levels of bis‑bibenzyls, while oil‑body formation remained largely unaffected, indicating these transporters are essential for metabolite accumulation rather than organelle biogenesis.
RNA sequencing of the halophyte Salicornia europaea revealed that combined hypoxia‑salt stress triggers a unique transcriptional response, with 16% of genes specifically altered and distinct synergistic, antagonistic, and additive effects across functional pathways. Metabolic analyses indicated enhanced sucrose and trehalose metabolism, a shift toward lactate fermentation, and increased proline synthesis, highlighting complex regulatory strategies for coping with concurrent stresses.
In a controlled dry-down experiment, Arabis sagittata showed significantly higher recovery from drought than the endangered Arabis nemorensis, a difference that could not be traced to a single major QTL, indicating a polygenic basis. Transcriptome and small‑RNA sequencing revealed that A. sagittata mounts a stronger transcriptional response, including species‑specific regulation of the conserved drought miRNA miR408, and machine‑learning identified distinct cis‑regulatory motif patterns underlying these divergent stress‑response networks.
The study characterizes the single-copy S-nitrosoglutathione reductase 1 (MpGSNOR1) in the liverwort Marchantia polymorpha, showing that loss-of-function mutants generated via CRISPR/Cas9 exhibit marked morphological defects and compromised SNO homeostasis and immune responses. These findings indicate that GSNOR-mediated regulation of S‑nitrosylation is an ancient mechanism linking development and immunity in early land plants.
The study examined whether colonisation by the arbuscular mycorrhizal fungus Rhizophagus irregularis primes immune responses in barley against the leaf rust pathogen Puccinia hordei. While AMF did not affect disease severity or plant growth, co‑infected leaves showed heightened expression of defence genes and transcriptome reprogramming, including altered protein ubiquitination, indicating a priming mechanism. These results highlight transcriptional and post‑translational pathways through which AMF can enhance barley disease resistance for sustainable crop protection.
The study examines how proteasomal degradation of A‑class and B‑class Auxin Response Factors (ARFs) is regulated in the bryophyte Marchantia polymorpha, identifying a key residue required for MpARF2 degradation that is also conserved in MpARF1. While disruption of MpARF2 degradation impairs development across life‑cycle stages, blocking MpARF1 degradation has minimal phenotypic impact, indicating divergent functional integration despite a shared degradation mechanism.
Molecular and Phenotypic Characterization of Telomere Repeat Binding (TRBs) Proteins in Moss: Evolutionary and Functional Perspectives
Authors: Kusova, A., Hola, M., Goffova Petrova, I., Rudolf, J., Zachova, D., Skalak, J., Hejatko, J., Klodova, B., Prerovska, T., Lycka, M., Sykorova, E., Bertrand, Y. J. K., Fajkus, J., Honys, D., Prochazkova Schrumpfova, P.
The study characterizes telomere repeat binding (TRB) proteins in the model moss Physcomitrium patens, demonstrating that individual PpTRB genes are essential for normal protonemal and gametophore development and that loss of TRBs leads to telomere shortening, mirroring findings in seed plants. Transcriptome analysis of TRB mutants shows altered expression of genes linked to transcription regulation and stimulus response, while subcellular localization confirms nuclear residence and mutual interaction of PpTRBs, underscoring their conserved role in telomere maintenance across land plants.