The study employed ultra large‑scale 2D clinostats to grow tomato (Solanum lycopersicum) plants beyond the seedling stage under simulated microgravity and upright control conditions across five sequential trials. Simulated microgravity consistently affected plant growth, but the magnitude and direction of the response varied among trials, with temperature identified as a significant co‑variant; moderate heat stress surprisingly enhanced growth under simulated microgravity. These results highlight the utility of large‑scale clinostats for dissecting interactions between environmental factors and simulated microgravity in plant development.
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.
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 examines how ectopic accumulation of methionine in Arabidopsis thaliana leaves, driven by a deregulated AtCGS transgene under a seed‑specific promoter, reshapes metabolism, gene expression, and DNA methylation. High‑methionine lines exhibit increased amino acids and sugars, activation of stress‑hormone pathways, and reduced expression of DNA methyltransferases, while low‑methionine lines show heightened non‑CG methylation without major transcriptional changes. Integrated transcriptomic and methylomic analyses reveal a feedback loop linking sulfur‑carbon metabolism, stress adaptation, and epigenetic regulation.
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.
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 investigated metabolic responses of kale (Brassica oleracea) grown under simulated microgravity using a 2-D clinostat versus normal gravity conditions. LC‑MS data were analyzed with multivariate tools such as PCA and volcano plots to identify gravity‑related metabolic adaptations and potential molecular markers for spaceflight crop health.
The study demonstrates that ABI5‑Binding Proteins (AFPs) interact with multiple components of the core ABA signaling pathway and serve as substrates for SnRK2 kinases and PP2C phosphatases, linking them to MAP kinases and 14‑3‑3 proteins. Phosphorylation of AFP2, promoted by ABA, stabilizes the protein and influences its subcellular localization, thereby modulating its ability to inhibit ABA responses during seed germination.
The study identifies the RNA‑binding protein AtG3BP1 as a phosphorylation target of MAPKs MPK3, MPK4, and MPK6 at Ser257 in Arabidopsis thaliana and shows that this modification promotes susceptibility to bacterial pathogens, suppresses ROS accumulation and salicylic acid biosynthesis, and maintains stomatal opening. Phospho‑mimic and phospho‑dead mutants reveal that phosphorylation stabilizes AtG3BP1 by preventing proteasomal degradation, highlighting a novel post‑translational control layer in plant immunity.