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 complete chloroplast genome of the endemic fruit species Dillenia philippinensis was sequenced, assembled, and annotated, revealing a 161,591‑bp quadripartite structure with 113 unique genes. Comparative analyses identified simple sequence repeats, codon usage patterns, and phylogenetic placement close to D. suffroticosa, providing a genomic resource for future breeding and conservation efforts.
The authors compiled and standardized published data on Rubisco dark inhibition for 157 flowering plant species, categorizing them into four inhibition levels and analyzing phylogenetic trends. Their meta‑analysis reveals a complex, uneven distribution of inhibition across taxa, suggesting underlying chloroplast microenvironment drivers and providing a new resource for future photosynthesis improvement efforts.
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 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 combined high-throughput image-based phenotyping with genome-wide association studies to uncover the genetic architecture of tolerance to the spittlebug Aeneolamia varia in 339 interspecific Urochloa hybrids. Six robust QTL were identified for plant damage traits, explaining up to 21.5% of variance, and candidate genes linked to hormone signaling, oxidative stress, and cell‑wall modification were highlighted, providing markers for breeding.
The study investigates how the timing of the vegetative phase change (VPC) in Arabidopsis thaliana influences drought adaptation, revealing strong genotype-by-environment interactions that create stage-specific fitness tradeoffs. Genotypes from warmer, drier Iberian climates transition earlier, and genome-wide association mapping identifies loci linked to VPC timing and drought response, with several candidates validated using T‑DNA insertion lines.
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.