CLPC2 plays specific roles in CLP complex-mediated regulation of growth, photosynthesis, embryogenesis and response to growth-promoting microbial compounds
Authors: Leal-Lopez, J., Bahaji, A., De Diego, N., Tarkowski, P., Baroja-Fernandez, E., Munoz, F. J., Almagro, G., Perez, C. E., Bastidas-Parrado, L. A., Loperfido, D., Caporalli, E., Ezquer, I., Lopez-Serrano, L., Ferez-Gomez, A., Coca-Ruiz, V., Pulido, P., Morcillo, R. J. L., Pozueta-Romero, J.
The study demonstrates that the plastid chaperone CLPC2, but not its paralogue CLPC1, is essential for Arabidopsis responsiveness to microbial volatile compounds and for normal seed and seedling development. Loss of CLPC2 alters the chloroplast proteome, affecting proteins linked to growth, photosynthesis, and embryogenesis, while overexpression of CLPC2 mimics CLPC1 deficiency, highlighting distinct functional roles within the CLP protease complex.
The mRNA covalent modification dihydrouridine regulates transcript turnover and photosynthetic capacity during plant abiotic stress
Authors: Yu, L., Melandri, G., Dittrich, A. C., Calleja, S., Rozzi, B., Ganguly, D. R., Palos, K., Srinivasan, A., Brewer, E. K., Fischer, H., Obata, T., Elgawad, H. A., Beemster, G. T. S., Henderson, R., Garcia, C. D., Zhang, X., Stern, D., Eveland, A., Schroeder, S. J., Skirycz, A., Lyons, E., Arnold, E. A., Gregory, B. D., Nelson, A. D. L., Pauli, D.
The study integrates multi-omics data from six Sorghum bicolor accessions under field drought to link RNA covalent modifications (RCMs) with photosynthetic performance, identifying the enzyme SbDUS2 that produces dihydrouridine (DHU) on transcripts. Loss‑of‑function dus2 mutants in Arabidopsis thaliana reveal that DHU deficiency leads to hyperstability of photosynthesis‑related mRNAs, impairing germination, development, and stress‑induced CO2 assimilation. The authors propose DHU as a post‑transcriptional mark that promotes rapid mRNA turnover during abiotic stress, enhancing plant resilience.
The study integrated metabolomic and transcriptomic analyses of red clover (Trifolium pratense) roots infected with Fusarium oxysporum and Phoma medicaginis to identify candidate cytochrome P450 enzymes responsible for the methylenedioxy bridge formation in (-)-maackiain biosynthesis. Using co‑expression network analysis and phylogenetic screening, five P450 candidates were selected and screened in engineered Saccharomyces cerevisiae, revealing TpPbS/CYP76F319 as the enzyme catalyzing conversion of calycosin to pseudobaptigenin. This discovery enables reconstruction of the complete (-)-maackiain pathway for potential health and agricultural applications.
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.
The study investigated how barley (Hordeum vulgare) adjusts mitochondrial respiration under salinity stress using physiological, biochemical, metabolomic and proteomic approaches. Salt treatment increased respiration and activated the canonical TCA cycle, while the GABA shunt remained largely inactive, contrasting with wheat responses.
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.
A meta‑analysis of 73 studies on cucumber (Cucumis sativus) under elevated CO₂ (eCO₂) revealed that eCO₂ significantly increased net photosynthetic rate (+56.31%), biomass (+27.75%) and yield (+21.98%), while reducing stomatal conductance (‑36.07%) and transpiration (‑30.42%). The authors recommend maintaining eCO₂ levels between 800–1200 ppm together with higher light, temperature, optimal humidity, and adequate fertilization to optimise greenhouse cucumber production under climate‑change scenarios.
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.