DECREASE IN DNA METHYLATION 1-mediated epigenetic regulation maintains gene expression balance required for heterosis in Arabidopsis thaliana
Authors: Matsuo, K., Wu, R., Yonechi, H., Murakami, T., Takahashi, S., Kamio, A., Akter, M. A., Kamiya, Y., Nishimura, K., Matsuura, T., Tonosaki, K., Shimizu, M., Ikeda, Y., Kobayashi, H., Seki, M., Dennis, E. S., Fujimoto, R.
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.
Authors: Ramires, M. J., Netherer, S., Schebeck, M., Hummel, K., Schlosser, S., Razzazi-Fazeli, E., Ertl, R., Ahmad, M., Espinosa-Ruiz, A., Carrera, E., Arc, E., Martinez-Godoy, M. A., Banos, J., Caballero, T., Ledermann, T., van Loo, M., Trujillo-Moya, C.
Using a controlled field experiment on clonal 35‑year‑old Norway spruce trees, the study examined molecular defense responses to Ips typographus attacks. A multi‑omics approach revealed rapid local increases in jasmonic acid and other phytohormones, leading to differential expression of up to 1,900 genes and corresponding proteomic and metabolomic changes that elevated deterrent compounds such as phenolic aglycones, diterpene resin acids, terpenes, and lignin.
The study demonstrates that the root endophytic fungus Colletotrichum tofieldiae promotes growth of various plant species under nitrogen-deficient conditions, a process that depends on Arabidopsis thaliana nitrate transporters and the fungal N‑utilization regulator CtAREA. Isotopic 15N tracing shows that the fungus transfers nitrogen to the host via a CtAREA-dependent but transporter‑independent pathway, while the associated bacterium Paraburkholderia monticola further enhances growth and suppresses fungal pathogenicity in certain host mutants.
The study applied a progressive, sublethal drought treatment to Arabidopsis thaliana, collecting time‑resolved phenotypic and transcriptomic data. Machine‑learning analysis revealed distinct drought stages driven by multiple overlapping transcriptional programs that intersect with plant aging, and identified high‑explanatory‑power transcripts as biomarkers rather than causal agents.
Salt stress strongly suppresses root growth in Festuca rubra while sparing shoot development. Transcriptome profiling identified over 68,000 differentially expressed genes, with up‑regulated genes enriched in methionine, melatonin, and suberin biosynthesis and down‑regulated genes involved in gibberellin, ABA, and sugar signaling, indicating extensive hormonal and metabolic reprogramming. Paradoxical regulation of gibberellin and ethylene pathways suggests a finely tuned balance between growth and stress responses.
The study integrates genome, transcriptome, and chromatin accessibility data from 380 soybean accessions to dissect the genetic and regulatory basis of symbiotic nitrogen fixation (SNF). Using GWAS, TWAS, eQTL mapping, and ATAC-seq, the authors identify key loci, co‑expression modules, and regulatory elements, and validate the circadian clock gene GmLHY1b as a negative regulator of nodulation via CRISPR and CUT&Tag. These resources illuminate SNF networks and provide a foundation for soybean improvement.
The study examined how single and repeated mechanical disturbances (whole‑pot drops) affect leaf folding in Mimosa pudica, using chlorophyll fluorescence to track photosystem II efficiency and transcriptome profiling to identify responsive genes. A single drop mainly up‑regulated flavonoid biosynthesis genes, whereas multiple drops triggered broader biotic and abiotic stress pathways, indicating a shift in the plant’s gene regulatory network under repeated stress.
Enhancement of Arabidopsis growth by Enterobacter sp. SA187 under elevated CO2 is dependent on ethylene signalling activation and primary metabolism reprogramming
Authors: Ilyas, A., Mauve, C., Pateyron, S., Paysant-Le Roux, C., Bigeard, J., Hodges, M., de Zelicourt, A.
The study shows that inoculating Arabidopsis thaliana with the plant‑growth‑promoting bacterium Enterobacter sp. SA187 markedly boosts root and shoot biomass under elevated CO₂, accompanied by altered nitrogen and carbon content and reshaped phytohormone signaling. Transcriptomic and metabolomic analyses reveal activation of salicylic acid, jasmonic acid, and ethylene pathways and enhanced primary metabolism, while the ethylene‑insensitive ein2‑1 mutant demonstrates that the growth benefits are ethylene‑dependent.
The study examined soybean (Glycine max) responses to simultaneous drought and Asian soybean rust infection using combined transcriptomic and metabolomic analyses. Weighted Gene Co-expression Network Analysis identified stress-specific gene modules linked to metabolites, while Copula Graphical Models uncovered sparse, condition‑specific networks, revealing distinct molecular signatures for each stress without overlapping genes or metabolites. The integrative approach underscores a hierarchical, modular defense architecture and suggests targets for breeding multi‑stress resilient soybeans.
Using integrated metabolomics, fluxomics, and proteomics, the study shows that Bamboo mosaic virus infection in Nicotiana benthamiana redirects carbon flux toward glycolysis and the TCA cycle, enhancing mitochondrial metabolism. Silencing the mitochondrial NAD⁺-dependent malic enzyme 1 disrupts cytoplasmic NADH/NAD⁺ balance and alters defense gene expression, indicating that mitochondrial redox regulation is crucial for antiviral defense.