Splicing regulation by RS2Z36 controls ovary patterning and fruit growth in tomato
Authors: Vraggalas, S., Rosenkranz, R. R., Keller, M., Perez-Perez, Y., Bachiri, S., Zehl, K., Bold, J., Simm, S., Ghatak, A., Weckwerth, W., Afjehi-Sadat, L., Chaturvedi, P., Testillano, P. S., Mueller-McNicoll, M., Zarnack, K., Fragkostefanakis, S.
The study identifies the serine/arginine-rich splicing factor RS2Z36 as a key regulator of ovary patterning and early fruit morphology in tomato, with loss‑of‑function mutants producing smaller, ellipsoid fruits and elongated pericarp cells. RNA‑seq and proteomic analyses reveal widespread alternative splicing and altered protein abundance, including novel splice‑variant peptides, while mutant pericarps show increased deposition of LM6‑detected arabinan and AGP epitopes.
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 functionally characterizes a conserved structured RNA motif (45ABC) in Arabidopsis RBP45 pre‑mRNAs, showing that its sequence and pairing elements mediate a negative auto‑ and cross‑regulatory feedback loop through alternative splicing that produces unproductive isoforms and reduces RBP45 expression. Transcriptome‑wide splicing analysis and phenotypic assessment of rbp45 mutants reveal that RBP45B plays a dominant role and that proper regulation of this motif is essential for root growth and flowering time.
Integrating physiological, transcriptomic, and cellular analyses, the study shows that olive fruit abscission zones undergo lignification, alkalization, and extensive cell‑wall remodeling during natural maturation and after ethephon treatment. A set of 733 FAZ‑specific genes, including β‑1,3‑glucanases, pectate lyases, and pH‑regulating transporters, were identified, and increased glucanase activity together with reduced plasmodesmata callose suggest enhanced intercellular communication facilitates organ detachment in this non‑climacteric fruit.
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.
A large-scale proteomic study in Arabidopsis thaliana identified over 32,000 isoform-specific peptides, confirming that alternative splicing, particularly intron retention, produces translated protein isoforms. Integrated proteogenomic analysis, SUPPA classification, and AlphaFold modeling revealed structural impacts and a non-linear regulation of transcript and protein abundance, with mutant phenotypes linking splicing to growth, chlorophyll content, and anthocyanin accumulation.
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.