Genetius

The study identifies a novel mRNA cleavage site within the coding region of the Arabidopsis immune regulator BIR1 and demonstrates that mutations at multiple cleavage sites increase BIR1 transcript and protein levels, implicating cis‑directed siRNA‑mediated degradation. It also reveals that the 5′‑UTR and a complementary lncRNA act as translational repressors, highlighting a multilayered regulatory network integrating sRNA‑guided cleavage and translation control during stress responses.

The study demonstrates that the circadian clock component ELF3 serves as a temporal gatekeeper for lateral root formation in Arabidopsis thaliana. ELF3 maintains rhythmic expression of key regulators, limiting hormone‑induced pericycle proliferation, while elf3 loss disrupts rhythms, enhances callus growth, and accelerates lateral root development via LNK1 and MADS‑box genes AGL14/AGL20. Hormonal signals can partially restore rhythmicity in elf3 mutants, revealing feedback between hormonal and circadian pathways.

The study reveals that the membrane‑localized kinases CRK2 and QSK1 coordinate their subcellular localization to regulate plasmodesmata callose deposition in Arabidopsis, balancing growth and osmotic stress responses. Under normal conditions CRK2 phosphorylates and retains QSK1 at the plasma membrane, while osmotic stress triggers QSK1 dephosphorylation and relocalization to plasmodesmata to promote callose synthesis, after which CRK2 also moves to plasmodesmata to limit excess deposition.

The study investigates the Arabidopsis homolog of human CENATAC, TITAN LIKE (TTL), revealing that the ttl-142 mutant shows reduced splicing efficiency of U12-dependent introns, especially AT‑AC introns, and associated morphological abnormalities. Compared to a DROL1 mutant, ttl-142 exhibits broader splicing defects but fewer gene expression changes, indicating distinct spliceosomal functions.

The study investigates how the plant NuA4 histone acetyltransferase complex interacts with histone deacetylases, focusing on HDA19, in Arabidopsis. Loss of HDA19 in a NuA4-deficient background exacerbates developmental defects and activates stress‑responsive genes, with transcriptional changes correlating strongly with increased H3K9 acetylation rather than H2A.Z acetylation. The results suggest NuA4 and HDA19 cooperate to modulate chromatin, where H3K9ac drives gene activation and H2A.Zac serves as a modulatory mark.

The study identifies a direct interaction between the transcription factors PLT3 and the thermosensor/circadian regulator ELF3 within the root stem cell niche of Arabidopsis thaliana, showing that ELF3 co‑localizes with PLT3 in cytoplasmic and nuclear condensates via their prion‑like domains. It further demonstrates that PIF3 and PIF4 act as nuclear shuttles for ELF3, linking environmental signals to the maintenance of quiescent center and columella stem cell fate.

The study demonstrates that cytokinin isoform activity in Arabidopsis is determined by the combined effects of receptor preference and metabolic persistence, with dihydrozeatin achieving strong anti‑senescence effects despite lower receptor affinity by accumulating to higher levels. Additionally, N‑glucoside forms can modulate signaling intensity in a ratio‑dependent manner, reducing cytokinin output when co‑applied with their corresponding bases.

The study demonstrates that Arabidopsis PHF1 interacts with SAR1 GTPases at ER exit sites, facilitating COPII-mediated export of PHT1 phosphate transporters. Using tobacco transient expression, split‑GFP, proximity labeling, and co‑immunoprecipitation, the authors show PHF1 preferentially binds the GDP‑locked form of SAR1, indicating a role in early COPII recruitment for ER export of PHT1.

The study demonstrates that the membrane‑localized kinase CRK5 acts as a negative regulator of salicylic‑acid‑mediated cell death and oxidative stress during dark‑induced senescence in Arabidopsis. Loss‑of‑function crk5 mutants exhibit accelerated senescence, heightened ROS accumulation, and altered antioxidant enzyme activities, phenotypes that are rescued by suppressing SA biosynthesis or catabolism, highlighting CRK5’s role in integrating hormonal and redox pathways.

The study maps phosphorylation of Arabidopsis thaliana RBR, showing that while most CDK‑site phosphorylations retain E2F binding, multi‑phosphorylation including the 911S site abolishes interaction with E2Fs and DREAM components and redirects RBR toward RNA‑binding proteins involved in ribosome biogenesis. The 911S phosphorylation peaks in proliferating cells and rapidly declines after DNA damage, suggesting it acts as a switch from proliferation to quiescence rather than the initial inhibitory event.