Genetius

The study identifies the AP2/ERF gene MpGMFR as essential for asexual reproduction in the liverwort Marchantia polymorpha, demonstrating that loss of MpGMFR blocks gemma and gemma cup formation while its inducible activation triggers their development. Transient strong activation even initiates gemma initial cells at the meristem that mature into functional propagules, indicating MpGMFR is both necessary and sufficient for initiating extra‑meristematic asexual structures.

The study uses laser‑ablation microscopy in the liverwort Marchantia to dissect the role of the first cell row and a contiguous stem‑cell quorum in apical notch meristem formation and regeneration, revealing intra‑ and inter‑notch communication that underlies auxin‑mediated apical dominance. Damage‑induced reorientation of notches demonstrates that stem cells act as a communicating population required for notch activity and meristem maintenance. A model integrating intra‑, inter‑ and extra‑notch signaling is proposed to guide future meristem research.

Members of the ACR3 transporter family from diverse plant lineages were cloned and functionally expressed in yeast, confirming their role as arsenic efflux transporters that provide varying resistance to arsenite and arsenate. The study reveals that some ACR3 proteins localize constitutively to the plasma membrane, while others undergo metalloid‑induced ER‑to‑plasma membrane trafficking, a process requiring the N‑terminal domain as demonstrated with Marchantia polymorpha ACR3.

The study identified 12 SABATH family genes in the liverwort Marchantia polymorpha and showed that MpSABATH2 is crucial for normal thallus growth and gemma cup formation; loss‑of‑function mutants exhibit severe growth inhibition and ectopic sexual branching resembling far‑red light responses. Transcriptomic and genetic analyses linked these defects to gibberellin metabolism, with GA biosynthesis inhibition partially rescuing the phenotype, indicating independent evolutionary acquisition of developmental roles by SABATH enzymes in land plants.

The study shows that carbon availability promotes gemma cup formation in Marchantia polymorpha by inducing cytokinin signaling, which upregulates the transcription factors MpGCAM1 and MpSTG. Constitutive cytokinin activation can rescue low‑sucrose conditions, while inhibition blocks sucrose‑induced gemma cup development, and this pathway operates independently of KAI2A/MAX2. The findings parallel carbon‑cytokinin interactions that drive axillary bud outgrowth in flowering plants.

The study reveals that the NPR protein in the liverwort Marchantia polymorpha uniquely regulates oil body formation and confers resistance to gastropod herbivory via interaction with the transcription factor MpERF13. Altered MpNPR levels disrupt MpERF13‑dependent gene expression and reduce defense against snail feeding, highlighting a lineage‑specific immune pathway in liverworts.

Red and blue light have opposite effects on the growth orientation of Marchantia polymorpha thalli, with red light promoting epinasty and blue light promoting hyponasty. Loss‑of‑function mutants in the respective photoreceptors (MpPHY and MpPHOT) and in two BBX transcription factors (MpBBX1 and MpBBX5) confirm that antagonistic red/blue signaling and antagonistic BBX activity balance to produce flat thalli. Time‑resolved transcriptomics identified rapid induction of all six MpBBX genes after light exposure.

The study shows that the Auxin Response Factor MpARF2 from Marchantia polymorpha forms nanoscopic clusters in the nucleus, a distinct mode of DNA binding separate from monomeric/oligomeric or phase‑separated condensate mechanisms. These nanoclusters provide high‑affinity, switch‑like, sequence‑specific binding, suggesting a novel mechanism for transcriptional regulation.

The study characterizes UV‑B signaling in the liverwort Marchantia polymorpha, demonstrating that the UVR8 photoreceptor forms a ground‑state homodimer that monomerizes and translocates to the nucleus upon UV‑B exposure, where it interacts with COP1 to trigger growth inhibition and protective gene expression. It further shows that RUP promotes UVR8 redimerization, SPA acts as a negative regulator, and HY5 has a limited antagonistic role, indicating that core UV‑B components existed in the ancestral land plant but their regulatory interactions have diversified over 400 million years.

The study characterizes the SWI3 chromatin regulator in the liverwort Marchantia polymorpha, showing that a promoter mutation disrupts male gametangiophore development and spermiogenesis while enhancing vegetative propagation. Transcriptomic analysis reveals MpSWI3 controls key genes governing reproductive initiation, sperm formation, and asexual reproduction, underscoring its ancient role in balancing vegetative and reproductive phases in land plants.