The study introduced charge-altering mutations into the N‑terminal region of Lhcb2 in Arabidopsis thaliana lacking native Lhcb2 to assess how intrinsic charge affects LHCII phosphorylation, state‑transition efficiency, and PSI‑LHCII complex formation. The R2E mutation drastically reduced Lhcb1/2 phosphorylation, impaired state transitions, and prevented PSI‑LHCII assembly, whereas the Q9E mutation had no measurable impact, and neither mutation altered thylakoid ultrastructure. Residual state transitions in the R2E line suggest that other Stn7 substrates can partially compensate for the loss of Lhcb2 phosphorylation.
The study reveals that rice perceives Xanthomonas oryzae pv. oryzae outer membrane vesicles through a rapid calcium signal that triggers plasma‑membrane nanodomain formation and the re‑organisation of defence‑related proteins, establishing an early immune response. Without this Ca2+ signal, OMVs are not recognized and immunity is weakened.
The study compares the iron-poor oceanic diatom Thalassiosira oceanica with the iron-rich coastal species T. pseudonana to uncover how diatoms adapt to low-iron conditions. Using photo‑physiological measurements, proteomic profiling, and focused ion beam scanning electron microscopy, the researchers show that each species remodels chloroplast compartments and exhibits distinct mitochondrial architectures to maintain chloroplast‑mitochondrial coupling under iron limitation.
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 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.
The study reveals that brassinosteroids activate phosphoenolpyruvate carboxykinase (PCK) by promoting dephosphorylation of conserved Ser-62 and Thr-66 residues, a process antagonized by the GSK3-like kinase BIN2. BR‑deficient Arabidopsis mutants exhibit reduced PCK activity, while phospho‑blocking mutations confer BR‑independent activation and enhanced seedling growth, and similar regulatory mechanisms are observed in maize and sorghum leaves.
The study generated deep proteome and phosphoproteome datasets from guard cell‑enriched tissue to examine how phosphorylation regulates stomatal movements. Comparative analysis revealed increased phosphorylation of endomembrane trafficking and vacuolar proteins in closed stomata, supporting a role for phospho‑regulated trafficking in stomatal dynamics.
Uncovering the Molecular Regulation of Seed Development and Germination in Endangered Legume Paubrasilia echinata Through Proteomic and Polyamine Analyses
Authors: Vettorazzi, R. G., Carrari-Santos, R., Sousa, K. R., Oliveira, T. R., Grativol, C., Olimpio, G., Venancio, T. M., Pinto, V. B., Quintanilha-Peixoto, G., Silveira, V., Santa-Catarna, C.
The study examined seed maturation and germination in the endangered legume Paubrasilia echinata using proteomic and polyamine analyses at 4, 6, and 8 weeks post-anthesis, identifying over 2,000 proteins and linking specific polyamines to developmental stages. Mature seeds (6 weeks) showed elevated proteasome components, translation machinery, LEA proteins, and heat shock proteins, while polyamine dynamics revealed putrescine dominance in early development and spermidine/spermine association with desiccation tolerance and germination. These findings uncover dynamic molecular shifts underlying seed development and provide insights for conservation and propagation.
EPP1 is an ancestral component of the plant Common SymbiosisPathway
Authors: Rich, M. K., Vernie, T., Tiwari, M., Chauderon, L., Causse, J., Pellen, T., Boussaroque, A., Bianconi, M. E., Vandenbussche, M., Chambrier, P., Le Ru, A., Castel, B., Nagalla, S., Cullimore, J., Keller, J., Valdes-Lopez, O., Mbengue, M., Ane, J.-M., Delaux, P.-M.
The study identifies EPP1 as a fourth, conserved component of the ancestral common symbiosis pathway required for intracellular plant–microbe interactions, showing that its loss impairs arbuscular mycorrhizal colonization across diverse plant clades. EPP1 is phosphorylated by the plasma‑membrane receptor SYRMK, and this modification is essential for downstream activation of the nuclear kinase CCaMK, positioning EPP1 upstream in the signaling cascade.
The study provides a comprehensive proteomic analysis of seed mitochondria from white lupin, revealing fully assembled OXPHOS complexes ready for immediate energy production upon imbibition. Quantitative mass‑spectrometry identified 1,162 mitochondrial proteins, highlighting tissue‑specific transporter and dehydrogenase profiles and dynamic remodeling during early germination, while many uncharacterized proteins suggest novel legume‑specific functions.