The study characterizes the liverwort-specific NPR protein (MpNPR) in Marchantia polymorpha, demonstrating that it controls oil body formation and confers resistance to gastropod herbivory through interaction with the transcription factor MpERF13. Loss- or gain-of-function of MpNPR disrupts MpERF13‑dependent gene expression and compromises defense against snail feeding, revealing a lineage‑specific immune pathway distinct from tracheophyte NPR functions.
The study demonstrates that red and blue light have opposing effects on thallus growth orientation in Marchantia polymorpha, with red light promoting epinasty and blue light promoting hyponasty. Loss-of-function mutants in the respective photoreceptors and BBX transcription factors reveal antagonistic interactions that balance thallus flatness under white light. Time‑resolved transcriptomics identified rapid light‑induced genes, including all six MpBBX members, whose mutant phenotypes support this antagonistic model.
Nanoclustering of a plant transcription factor enables strong yet specific DNA binding
Authors: Arfman, K., Janssen, B. P. J., Romein, R., van den Boom, S., van der Woude, M., Jansen, L., Rademaker, M., Hernandez-Garcia, J., Ramalho, J. J., Dipp-Alvarez, M., Borst, J. W., Weijers, D., van Mierlo, C. P. M., Sprakel, J.
The study reveals that the Auxin Response Factor MpARF2 in Marchantia polymorpha forms nanoscopic clusters within the plant nucleus, representing a distinct mode of DNA binding distinct from monomeric/oligomeric binding and liquid phase-separated condensates. These nanoclusters provide high‑affinity, switch‑like, sequence‑specific DNA interaction, suggesting a novel mechanism for transcriptional regulation by TF nanoclustering.
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 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.
KATANIN promotes cell elongation and division to generate proper cell numbers in maize organs
Authors: Martinez, S. E., Lau, K. H., Allsman, L. A., Irahola, C., Habib, C., Diaz, I. Y., Ceballos, I., Panteris, E., Bommert, P., Wright, A. J., Weil, C., Rasmussen, C.
The study identifies two maize genes, Discordia3a and Discordia3b, that encode the microtubule‑severing protein KATANIN. Loss‑of‑function allele combinations reduce microtubule severing, impair cell elongation, delay mitotic entry, and disrupt preprophase band and nuclear positioning, leading to dwarfed, misshapen plants.
Six new Viola species and two reinstated species from China were identified using field surveys, detailed morphological comparison, and phylogenetic analysis of ITS and GPI gene sequences, placing them in section Plagiostigma subsect. Diffusae. The GPI data offered higher resolution, indicating complex relationships possibly due to ancient hybridization or incomplete lineage sorting, thereby clarifying species boundaries and evolutionary patterns in Chinese Viola.
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 identified lineage-specific long non‑coding RNAs (lncRNAs) from the aphid‑specific Ya gene family in Rhopalosiphum maidis and R. padi, demonstrating that these Ya lncRNAs are secreted into maize, remain stable, and move systemically. RNA interference of Ya genes reduced aphid fecundity, while ectopic expression of Ya lncRNAs in maize enhanced aphid colonization, indicating that Ya lncRNAs act as cross‑kingdom effectors that influence aphid virulence.