Genetius

The study investigates the role of the bZIP transcription factor HY5 in Arabidopsis thaliana’s tolerance to combined high‑light and heat stress (HLHS). HY5 overexpression enhances photosynthetic efficiency, reduces membrane damage, and improves leaf health under HLHS, while HY5 deficiency leads to hypersensitivity, linked to altered accumulation of photosystem II proteins, impaired non‑photochemical quenching via NPQ4/PsbS, and disrupted ABA and JA signaling. Proteomic and hormonal analyses reveal HY5 as a central regulator coordinating photoprotective proteins and hormone networks under multifactorial stress.

Using a forward genetic screen of 284 Arabidopsis thaliana accessions, the study identified extensive natural variation in root endodermal suberin and pinpointed the previously unknown gene SUBER GENE1 (SBG1) as a key regulator. GWAS and protein interaction analyses revealed that SBG1 controls suberin deposition by binding type‑one protein phosphatases (TOPPs), with disruption of this interaction or TOPP loss‑of‑function altering suberin levels, linking the pathway to ABA signaling.

The study examined how Turnip mosaic virus (TuMV) infection reshapes root-associated bacterial and fungal communities in two Arabidopsis thaliana genotypes. TuMV markedly reduced bacterial diversity and altered community composition in a genotype‑specific manner, while fungal communities stayed stable; bacterial co‑occurrence networks later recovered and even increased in complexity, highlighting microbial resilience. These findings underscore virus‑driven selective filtering of bacterial root microbiota and the role of host genotype in mediating microbiome responses to viral stress.

Using Arabidopsis thaliana cat2 knockout plants complemented with transgenic Helicobacter pylori catalase isoforms, the study demonstrates that peroxisomal catalase is essential for H₂O₂ homeostasis and suppressing non‑enzymatic decarboxylation, thereby supporting normal growth and net carbon fixation. However, once a minimal catalase capacity is restored, further increases in enzyme activity yield limited gains in photosynthetic performance.

The study characterizes the mitochondrial P‑type PPR protein PPR9 in Arabidopsis thaliana, demonstrating that loss of PPR9 causes embryonic arrest, delayed germination, stunted growth, and impaired complex I respiration due to defective splicing of several group II introns (nad2 intron 3, nad7 introns 1 and 2). Using an embryo‑rescue approach to maintain homozygous mutants, molecular analyses reveal that PPR9 is essential for mitochondrial intron splicing and proper respiratory complex I biogenesis, linking nuclear‑encoded RNA processing to plant development and energy metabolism.

The study identifies a non‑canonical H3.3 K27/K36 di‑acetylation mark as a specific substrate of the histone deacetylase HDA19, whose removal under salinity stress is impaired in hda19 mutants, leading to increased LEA protein accumulation and enhanced salt tolerance. Mimicking this di‑acetylation via K→Q substitutions reproduces the hda19 phenotype, and loss of key LEA genes abolishes the tolerance, establishing H3.3 di‑acetylation as a core epigenetic mechanism for stress resilience in Arabidopsis.

The study examined Arabidopsis thaliana transcriptome dynamics during gradual heat acclimation and subsequent lethal heat shock, identifying gene groups and pathways that constitute a heat transcriptional memory. Experimental work highlighted the role of flavonoids in heat tolerance and revealed that stomatal density and aperture changes in acclimated plants may be regulated by the AGL16 transcription factor and its microRNA regulator miR824.

The authors introduce an in situ cryo‑etching workflow using a gas cluster ion beam and a titanium ridge mask to prepare frozen Arabidopsis thaliana seed sections directly within a ToF‑SIMS instrument, eliminating the need for chemical fixation or cryo‑transfer. This approach yields flat, artifact‑free surfaces that preserve tissue architecture and molecular integrity, enabling subcellular imaging at ~1 µm resolution with intact mass spectra up to 1000 Da.

The study defines 31 °C as a non‑lethal thermal stress for Arabidopsis thaliana and shows that it reduces primary root growth, meristem size, and superoxide accumulation while restricting PLT2 distribution. Development‑zone‑specific transcriptomics revealed down‑regulation of RGFs, their receptors, and PLT2, and functional assays demonstrated that RGF treatment rescues these defects and promotes lateral root elongation, indicating that the RGF‑RGFR‑PLT2 pathway, rather than the canonical heat‑shock response, mediates root adaptation to moderate heat stress.

The study demonstrates that the plastid chaperone CLPC2, but not its paralogue CLPC1, is essential for Arabidopsis responsiveness to microbial volatile compounds and for normal seed and seedling development. Loss of CLPC2 alters the chloroplast proteome, affecting proteins linked to growth, photosynthesis, and embryogenesis, while overexpression of CLPC2 mimics CLPC1 deficiency, highlighting distinct functional roles within the CLP protease complex.