Genetius

The study examined how DNA methylation influences cold stress priming in Arabidopsis thaliana, revealing that primed plants exhibit distinct gene expression and methylation patterns compared to non-primed plants. DNA methylation mutants, especially met1 lacking CG methylation, showed altered cold memory and misregulation of the CBF gene cluster, indicating that methylation ensures transcriptional precision during stress recall.

The study integrates multi-omics data from six Sorghum bicolor accessions under field drought to link RNA covalent modifications (RCMs) with photosynthetic performance, identifying the enzyme SbDUS2 that produces dihydrouridine (DHU) on transcripts. Loss‑of‑function dus2 mutants in Arabidopsis thaliana reveal that DHU deficiency leads to hyperstability of photosynthesis‑related mRNAs, impairing germination, development, and stress‑induced CO2 assimilation. The authors propose DHU as a post‑transcriptional mark that promotes rapid mRNA turnover during abiotic stress, enhancing plant resilience.

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.

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 integrated 16 Arabidopsis thaliana whole‑genome bisulfite sequencing datasets from 13 stress experiments using a unified bioinformatic pipeline to map common and stress‑specific DNA methylation changes. Differentially methylated regions varied by stress type and methylation context, with CG DMRs enriched in gene bodies and CHG/CHH DMRs in transposable elements, some of which overlapped loci prone to stable epimutations. Gene ontology and TE enrichment analyses highlighted shared stress pathways and suggest environmental stress can generate heritable epigenetic variation.

Using genome‑wide association studies in Arabidopsis thaliana, the authors identified the chromatin‑associated protein CDCA7 as a trans‑regulator that specifically controls CG methylation (mCG) and TE silencing. CDCA7 and its paralog CDCA7β bind the remodeler DDM1, modulating its activity without broadly affecting non‑CG methylation or histone variant deposition, and natural variation in CDCA7 regulatory sequences correlates with local ecological adaptation.

The study demonstrates that the chromatin remodeler DDM1 is essential for biomass heterosis in Arabidopsis thaliana hybrids, as loss of DDM1 function leads to reduced rosette growth and extensive genotype‑specific transcriptomic and DNA methylation changes. Whole‑genome bisulfite sequencing revealed widespread hypomethylation in ddm1 mutants, while salicylic acid levels were found unrelated to heterosis, indicating that epigenetic divergence, rather than SA signaling, underpins hybrid vigor.

The study identifies GyrB3 as a novel nuclear factor that interacts with histone deacetylases to regulate transposable element silencing in plants, acting as a suppressor of IBM1 deficiency–induced epigenetic defects. Loss of GyrB3 reduces DNA methylation and increases H3 acetylation at TEs, demonstrating the importance of histone deacetylation for genome stability.

The authors established a live‑cell imaging platform that combines confocal microscopy of genetically encoded fluorescent protein biosensors with on‑stage illumination to monitor pH, MgATP²⁻, and NADH/NAD⁺ dynamics during dark‑light transitions in Arabidopsis mesophyll cells. They discovered that photosynthetic proton pumping triggers a stromal alkalinization wave extending to the cytosol and mitochondria, elevates MgATP²⁻ levels, and drives reduction of the NAD pool, with malate dehydrogenase mutants showing altered cytosolic redox even in darkness. This methodological advance enables high‑resolution mapping of photosynthesis‑linked energy physiology across cellular compartments.

The study compared photosynthetic performance and carbon metabolism in mature versus immature leaves of Arabidopsis thaliana accessions from different latitudes under standard and low‑temperature/high‑light conditions. Leaf‑specific measurements of Fv/Fm and CO2 assimilation revealed distinct acclimation capacities, and integration of carbohydrate and carboxylic‑acid profiles into a carbon balance model indicated that mature leaves help stabilize metabolism in younger tissue. The authors emphasize the importance of accounting for intra‑rosette heterogeneity to avoid misleading metabolic interpretations.