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 characterizes the chloroplast‑localized protein AT4G33780 in Arabidopsis thaliana using CRISPR/Cas9 knockout and overexpression lines, revealing tissue‑specific expression and context‑dependent effects on seed germination, seedling growth, vegetative development, and root responses to nickel stress. Integrated transcriptomic (RNA‑seq) and untargeted metabolomic analyses show extensive transcriptional reprogramming—especially of cell‑wall genes—and altered central energy metabolism, indicating AT4G33780 coordinates metabolic state with developmental regulation rather than controlling single pathways.

The study examined the roles of AtKUP2, AtKUP6, AtKUP8, and GORK potassium transport proteins in guard cell function by performing gas-exchange measurements on mature Arabidopsis leaves. Loss of KUP2/6/8 reduced stomatal conductance, whereas a GORK loss‑of‑function mutant showed increased conductance, yet the magnitude of light‑ and ABA‑induced transpiration changes remained similar across genotypes, suggesting a limited dynamic range for rapid stomatal movements that relies on small ionic osmolytes.

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 shows that Arabidopsis root tips adapt to hypoxia by increasing H3K4me3 levels, linked to the inhibition of group 7 demethylases (KDM7s). Genetic loss of KDM7s mimics hypoxic conditions, activating genes that sustain meristem survival, suggesting KDM7s act as root‑specific oxygen sensors that prime epigenetic tolerance mechanisms.

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 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 reveals that the methyl‑CpG‑binding domain protein MBD8 interacts with the histone demethylase LDL2 to facilitate removal of H3K4me1 and transcriptional repression downstream of H3K9me2 in Arabidopsis. MBD8 binds GC‑poor DNA independently of cytosine methylation and stabilizes LDL2 protein levels, indicating a broader role for MBD proteins beyond methyl‑DNA recognition.