Genetius

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.

The study investigates the function of two GT47B arabinan arabinosyltransferases in the liverwort Marchantia polymorpha, generating loss‑of‑function and overexpression lines to assess cell wall composition. Using CoMPP, glycosyl linkage analysis, and LM6 immunolabelling, the authors found that MpARADL2 mutants have reduced 1,5‑L‑arabinan epitopes in elaters despite unchanged overall 5‑linked Araf levels, suggesting additional enzymes compensate in thallus tissue. Attempts to express and purify the enzymes in HEK293 cells failed, implying a clade‑specific solubility requirement and highlighting the need to identify interacting partners.

The study investigated meristem activation in the liverwort Marchantia polymorpha, revealing that simulated shade causes alternating inactivity of meristems. Transcriptomic comparison of active versus inactive meristems identified the cytochrome P450 monooxygenase MpCYP78E1 as an inhibitor of meristem activity and initiation, with loss- and gain-of-function mutants confirming its regulatory role in shoot branching architecture.

The authors identified MpCAFA, a protein combining CAPS-like and FAP115-like domains, as a key factor for rapid ciliary swimming in the liverwort Marchantia polymorpha spermatozoids. Loss-of-function mutants displayed markedly reduced swimming speed despite normal axoneme structure, chemotaxis, and fertility, and these defects were rescued by a MpCAFA‑mCitrine fusion that localized along the entire cilium. Both the CAPS-like and FAP115-like regions are required for MpCAFA’s function and ciliary targeting, establishing it as a major ciliary protein and a marker for visualizing spermatozoid motility.

The study characterizes the composition and structure of cell wall glycans in eight tissue types of the liverwort Marchantia polymorpha, revealing both typical land‑plant features and unique traits such as abundant (1,5)-arabinan in sporophytes and low overall pectin levels. Comparative genomic analysis shows a diversified glycosyltransferase repertoire relative to Arabidopsis, and the authors created a Gateway‑compatible library of 93 M. polymorpha GTs to facilitate future functional studies.

The study demonstrates that MYB‑bHLH‑WDR transcriptional complexes (MBW) are present in the liverwort Marchantia polymorpha, indicating that such complexes originated before the diversification of land plants. Functional analyses reveal that two MYB paralogs, MpMYB14 and MpMYB02, rely on a single bHLH partner (MpbHLH12) to regulate flavonoid biosynthesis and liverwort‑specific oil body maturation, suggesting an ancestral role in pigment production and a derived role in organelle development.

The authors adapted OpenPlant kit CRISPR/Cas9 tools to enable multiplex gRNA expression from a single transcript using tRNA sequences in the liverwort Marchantia polymorpha, markedly enhancing editing efficiency and scalability. They coupled this vector system with a simplified, optimized thallus transformation protocol, providing a rapid and versatile platform for generating CRISPR/Cas9 mutants and advancing functional genomics in this model species.

The study characterizes MpACR3, an ACR3 transporter from the liverwort Marchantia polymorpha, demonstrating its role as a metalloid/proton antiporter that provides resistance to arsenic and moderate tolerance to antimony. The authors reveal an N‑terminal arsenic‑sensing domain that controls Golgi retention and plasma‑membrane trafficking via cysteine‑mediated conformational changes, and show that a conserved arginine motif influences both membrane accumulation and transport activity. These findings suggest a plant‑specific adaptation of ACR3 transporters to arsenic toxicity.

The study used comparative transcriptomics to examine how Fusarium oxysporum isolates with different lifestyles on angiosperms regulate effector genes during infection of the non‑vascular liverwort Marchantia polymorpha. Core effector genes on fast core chromosomes are actively expressed in the bryophyte host, while lineage‑specific effectors linked to angiosperm pathogenicity are silent, and disruption of a compatibility‑associated core effector alters the expression of other core effectors, highlighting conserved fungal gene networks across plant lineages.

Phylogenetic analysis reveals that non‑seed plants, exemplified by the liverwort Marchantia polymorpha, possess a streamlined repertoire of cyclin and CDK genes, with only three cyclins active in a phase‑specific manner during vegetative development. Single‑cell RNA‑seq and fluorescent reporter assays, combined with functional overexpression studies, demonstrate the distinct, non‑redundant roles of MpCYCD;1, MpCYCA, and MpCYCB;1 in G1 entry, S‑phase progression, and G2/M transition, respectively.