Genetius

The study used Arabidopsis thaliana mutants with low (vtc2, vtc4) and high (vtc2/OE-VTC2) ascorbate levels to examine how ascorbate concentration affects gene expression and cellular homeostasis. Transcriptomic analysis revealed that altered ascorbate levels modulate defense and stress pathways, and that TAA1/TAR2‑mediated auxin biosynthesis is required for coping with elevated ascorbate in a light‑dependent manner.

The study uses time-course microscopy to show that VAR2 mutants have delayed and heterogeneous chloroplast biogenesis, with many cells lacking chloroplasts, especially in white leaf sectors. Genetic interactions reveal that loss of plastid division genes worsens the phenotype, while overexpressing PDV1/PDV2 or knocking out COP1 rescues it, indicating VAR2’s novel role in plastid division and chloroplast development. These findings clarify mechanisms behind leaf variegation.

The study compares transcriptional, proteomic, and metabolomic responses of wild‑type Arabidopsis and a cyp71A27 mutant to a plant‑growth‑promoting Pseudomonas fluorescens strain and a pathogenic Burkholderia glumeae strain, revealing distinct reprogramming and an unexpected signaling role for the non‑canonical P450 CYP71A27. Mutant analysis showed that loss of CYP71A27 alters gene and protein regulation, especially during interaction with the PGP bacterium, while having limited impact on root metabolites and exudates.

The study identifies the scaffolding protein RACK1A as a cytoplasmic interaction partner of the antioxidant enzyme FSD1, revealing that RACK1A recruits FSD1 to cycloheximide-sensitive condensates that colocalize with stress granules during salt stress. Functional analyses show that this RACK1A‑FSD1 module modulates ROS levels, influences root hair tip growth, and determines salt‑stress resilience in Arabidopsis.

The study identifies four Arabidopsis REM transcription factors (VDD, VAL, REM12, REM13) that bind specific DNA sequences and, together with GDE1, recruit RNA polymerase IV to produce 24‑nt siRNAs that direct DNA methylation at designated loci. Loss of GDE1 causes Pol IV complexes to relocalize to sites bound by REM8, indicating that REM proteins provide sequence‑specific cues for epigenetic patterning.

The study investigates how miR394 influences flowering time in Arabidopsis thaliana by combining transcriptomic profiling of mir394a mir394b double mutants with histological analysis of reporter lines. Bioinformatic analysis identified a novel lncRNA overlapping MIR394B (named MIRAST), and differential promoter activity of MIR394A and MIR394B suggests miR394 fine‑tunes flower development through transcription factor and chromatin remodeler regulation.