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 evaluated a transgenic soybean line (VPZ-34A) expressing Arabidopsis VDE, PsbS, and ZEP for combined improvements in light‑use efficiency and carbon assimilation under ambient and elevated CO2 in a FACE experiment. While VPZ‑34A showed enhanced maximum quantum efficiency of PSII under fluctuating light, it did not increase carbon assimilation efficiency or yield, and transcriptome analysis revealed limited gene expression changes. The results suggest that VPZ‑mediated photosynthetic gains are insufficient to boost productivity under elevated CO2.
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 identified two wheat genes tightly linked to the triple pistil (TP) phenotype and created functional co‑dominant markers for early selection. CRISPR‑Cas9 editing of one gene converted TP florets to single‑grain florets, while field evaluation showed TP wheat increases grains per spike without reducing grain weight, highlighting its breeding value.
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 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.
Unravelling the intraspecific variation in drought responses in seedlings of European black pine (Pinus nigra J.F. Arnold)
Authors: Ahmad, M., Hammerbacher, A., Priemer, C., Ciceu, A., Karolak, M., Mader, S., Olsson, S., Schinnerl, J., Seitner, S., Schoendorfer, S., Helfenbein, P., Jakub, J., Breuer, M., Espinosa, A., Caballero, T., Ganthaler, A., Mayr, S., Grosskinsky, D. K., Wienkoop, S., Schueler, S., Trujillo-Moya, C., van Loo, M.
The study examined drought tolerance across nine provenances of the conifer Pinus nigra using high‑throughput phenotyping combined with metabolomic and transcriptomic analyses under controlled soil‑drying conditions. Drought tolerance, measured by the decline in Fv/Fm, varied among provenances but was not linked to a climatic gradient and was independent of growth, with tolerant provenances showing distinct flavonoid and diterpene profiles and provenance‑specific gene expression patterns. Integrating phenotypic and molecular data revealed metabolic signatures underlying drought adaptation in this non‑model conifer.
The study systematically identified heterosis-associated genes and metabolites in rice, functionally validated three genes influencing seedling length, and integrated these molecules into network modules to explain heterosis variance. Predominant additive and partially dominant inheritance patterns were linked to parental genomic variants and were shown to affect 17 agronomic traits in rice, as well as yield heterosis in maize and biomass heterosis in Arabidopsis. The work highlights the quantitative contribution of transcriptomic and metabolomic variation, especially in phenylpropanoid biosynthesis, to hybrid vigor.
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.