Genetius

The study demonstrates that the interaction between spliceosomal proteins STA1 and DOT2 controls nuclear speckle organization, pre‑mRNA splicing efficiency, and heat‑stress tolerance in Arabidopsis thaliana. A missense mutation in DOT2 restores the weakened STA1‑DOT2 interaction in the sta1‑1 mutant, linking interaction strength to speckle formation and transcriptome‑wide intron retention under heat stress, while pharmacological inhibition of STA1‑associated speckles reproduces the mutant phenotypes. These findings reveal a heat‑sensitive interaction node that couples spliceosome assembly to nuclear speckle dynamics and splicing robustness.

The study identified a heat‑responsive exon‑skipping event in the basic Helix‑Loop‑Helix domain of the transcription factor PIF4, which reduces PIF4 activity and promotes photomorphogenic traits in etiolated seedlings. This reveals a novel post‑transcriptional mechanism by which plants modulate PIF4 function during heat stress.

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 reveals that heat tolerance of meiotic division in Arabidopsis thaliana depends on sustained translation of cell‑cycle genes mediated by the protein TAM, which forms specialized condensates under high temperature. Natural variation was used to identify heat‑sensitive and heat‑tolerant TAM alleles, and boosting TAM translation with complementary peptides rescued heat‑induced meiotic defects, highlighting a potential mechanism driving polyploidisation under climate stress.

The study examined the impact of daily moderate heat stress (38 °C for 4 h) on Arabidopsis thaliana, revealing altered thylakoid ultrastructure and structurally intact but functionally impaired PSII‑LHCII complexes. A pronounced reduction in cytochrome b6f content limited PSI on the donor side, suggesting that Cyt b6f down‑regulation serves as an acclimation mechanism that protects PSI at the expense of overall photosynthetic efficiency.

The study compared two plasma‑activated water (PAW) solutions with differing H2O2 concentrations on Arabidopsis thaliana, showing that PAW lacking detectable H2O2 enhanced seedling growth and induced nitrogen‑uptake genes, whereas H2O2‑containing PAW did not affect growth but improved root growth under heat stress. Mature plants fertilized with H2O2‑free PAW performed comparably to nitrate controls, demonstrating PAW can serve as an effective alternative N fertilizer if H2O2 levels are carefully managed.

The study shows that m6A RNA methylation acts as a negative regulator of thermotolerance in Arabidopsis. Loss of m6A increases heat‑responsive gene transcripts and mRNA stability, and reduces m6A during heat shock, which together enhance H3K4me3 enrichment and heat shock protein accumulation. These results reveal an interplay between m6A methylation and histone modifications that modulates heat stress responses.

The study examined how Arabidopsis thaliana integrates physiological, genetic, hormonal, and transcriptomic responses to combined water deficit, heat stress, and elevated CO2. Results show that stomatal aperture under these complex stress combinations is governed by a specific set of regulators, including nitric oxide, OPEN STOMATA 1, and the SLAH3 anion channel, distinct from those active under simpler stress conditions. This reveals a hierarchical stomatal stress code that could inform future research on plant resilience to global change.

The study examined how heat stress alters lipid droplets (LDs) and their lipidome in Arabidopsis thaliana roots, including analysis of LDs from a specific Arabidopsis mutant. Heat stress caused membrane lipid degradation, increased TAGs and LDs, and revealed novel LD-associated proteins, notably triterpene biosynthetic enzymes whose substrates and products accumulate in root LDs, suggesting LDs act as both sinks and sources during stress and in specialized metabolism.