In vivo binding by Arabidopsis SPLICING FACTOR 1 shifts 3' splice site choice, regulating circadian rhythms and immunity in plants
Authors: Agrofoglio, Y. C., Iglesias, M. J., de Leone, M. J., Hernando, C. E., Lewinski, M., Torres, S. B., Contino, G., Yanovsky, M. J., Staiger, D., Mateos, J. L.
The study characterizes the plant spliceosomal protein AtSF1 in Arabidopsis thaliana, using iCLIP and RNA‑seq to map its in vivo branch point binding sites and demonstrate that loss of AtSF1 causes widespread 3' splice‑site mis‑selection. Structural comparison reveals a plant‑specific domain architecture, and the identified AtSF1 targets are enriched for circadian and defense genes, linking splicing regulation to timing and immunity.
The study evaluated how stomatal anatomy and physiological efficiency influence wheat heat tolerance across multi‑environment field trials with 200 genotypes, using early versus delayed sowing to impose temperature stress. Findings revealed a decoupling between anatomical capacity (gsmax) and actual conductance (gs, gse) under heat, plastic shifts toward smaller, denser stomata, and identified 125 QTL linked to stomatal traits, suggesting targets for breeding climate‑resilient wheat.
Evolution of HMA-integrated tandem kinases accompanied by expansion of target pathogens
Authors: Asuke, S., Tagle, A. G., Hyon, G.-S., Koizumi, S., Murakami, T., Horie, A., Niwamoto, D., Katayama, E., Shibata, M., Takahashi, Y., Islam, M. T., Matsuoka, Y., Yamaji, N., Shimizu, M., Terauchi, R., Hisano, H., Sato, K., Tosa, Y.
The study cloned the resistance genes Rmo2 and Rwt7 from barley and wheat, revealing them as orthologous tandem kinase proteins (TKPs) with an N‑terminal heavy metal‑associated (HMA) domain. Domain‑swapping experiments indicated that the HMA domain dictates effector specificity, supporting a model of TKP diversification into paralogs and orthologs that recognize distinct pathogen effectors.
The study identified a critical two‑week window of elevated maternal temperature during weeks 4–5 after flowering that delays dormancy release in weedy rice seeds. Controlled‑environment and field transplant experiments showed that this late‑reproductive‑stage heat exposure postpones germination after after‑ripening, providing insight for predicting seed behavior and improving weed management strategies.
Mutations in the plastid division gene PARC6 and the granule initiation gene BGC1 were combined to generate wheat plants with dramatically enlarged A-type starch granules, some exceeding 50 µm, without affecting plant growth, grain size, or overall starch content. The parc6 bgc1 double mutant was evaluated in both glasshouse and field trials, and the giant granules displayed altered viscosity and pasting temperature, offering novel functional properties for food and industrial applications.
Using a forward genetic screen of 284 Arabidopsis thaliana accessions, the study identified extensive natural variation in root endodermal suberin and pinpointed the previously unknown gene SUBER GENE1 (SBG1) as a key regulator. GWAS and protein interaction analyses revealed that SBG1 controls suberin deposition by binding type‑one protein phosphatases (TOPPs), with disruption of this interaction or TOPP loss‑of‑function altering suberin levels, linking the pathway to ABA signaling.
Glycosylated diterpenes associate with early containment of Fusarium culmorum infection across wheat (Triticum aestivum L.) genotypes under field conditions
Authors: Pieczonka, S. A., Dick, F., Bentele, M., Ramgraber, L., Prey, L., Kupczyk, E., Seidl-Schulz, J., Hanemann, A., Noack, P. O., Asam, S., Schmitt-Kopplin, P., Rychlik, M.
The researchers performed a large‑scale field trial with 105 wheat (Triticum aestivum) genotypes inoculated by Fusarium culmorum, combining quantitative deoxynivalenol (DON) profiling and untargeted metabolomics to uncover molecular signatures of infection. Sesquiterpene‑derived metabolites tracked toxin accumulation, whereas glycosylated diterpene conjugates were enriched in low‑DON samples, indicating a potential defensive metabolic pathway.
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 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.
The study examined DNA methylation dynamics in Arabidopsis thaliana shoots and roots under heat, phosphate deficiency, and combined stress using whole-genome bisulfite sequencing, small RNA‑seq, and RNA‑seq. Distinct stress‑specific methylation patterns were identified, with heat and combined stress causing CHH hypomethylation, phosphate deficiency causing hyper‑ and hypomethylation in shoots and roots respectively, and the combined stress exhibiting a unique signature independent of additive effects. Methylation changes were concentrated in transposable elements and regulatory regions, implicating RdDM and CMT2 pathways and suggesting a role in chromatin accessibility rather than direct transcriptional control.