The study applied a progressive, sublethal drought treatment to Arabidopsis thaliana, collecting time‑resolved phenotypic and transcriptomic data. Machine‑learning analysis revealed distinct drought stages driven by multiple overlapping transcriptional programs that intersect with plant aging, and identified high‑explanatory‑power transcripts as biomarkers rather than causal agents.
Enhancement of Arabidopsis growth by Enterobacter sp. SA187 under elevated CO2 is dependent on ethylene signalling activation and primary metabolism reprogramming
Authors: Ilyas, A., Mauve, C., Pateyron, S., Paysant-Le Roux, C., Bigeard, J., Hodges, M., de Zelicourt, A.
The study shows that inoculating Arabidopsis thaliana with the plant‑growth‑promoting bacterium Enterobacter sp. SA187 markedly boosts root and shoot biomass under elevated CO₂, accompanied by altered nitrogen and carbon content and reshaped phytohormone signaling. Transcriptomic and metabolomic analyses reveal activation of salicylic acid, jasmonic acid, and ethylene pathways and enhanced primary metabolism, while the ethylene‑insensitive ein2‑1 mutant demonstrates that the growth benefits are ethylene‑dependent.
The study combined cell biology, transcriptomics, and ionomics to reveal that zinc deficiency reduces root apical meristem size while preserving meristematic activity and local Zn levels, leading to enhanced cell elongation and differentiation in Arabidopsis thaliana. ZIP12 was identified as a highly induced gene in the zinc‑deficient root tip, and zip12 mutants displayed impaired root growth, altered RAM structure, disrupted Zn‑responsive gene expression, and abnormal metal partitioning, highlighting ZIP12’s role in maintaining Zn homeostasis and meristem function.
Arabidopsis lines with modified ascorbate concentrations reveal a link between ascorbate and auxin biosynthesis
Authors: Fenech, M., Zulian, V., Moya-Cuevas, J., Arnaud, D., Morilla, I., Smirnoff, N., Botella, M. A., Stepanova, A. N., Alonso, J. M., Martin-Pizarro, C., Amorim-Silva, V.
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 identifies the serine/threonine protein kinase CIPK14/SNRK3.15 as a regulator of sulfate‑deficiency responses in Arabidopsis thaliana seedlings, with mutants showing diminished early adaptive and later salvage responses under sulfur starvation. While snrk3.15 mutants exhibit no obvious phenotype under sufficient sulfur, the work provides a novel proteomic dataset comparing wild‑type and mutant seedlings under sulfur limitation.
Revisiting the Central Dogma: the distinct roles of genome, methylation, transcription, and translation on protein expression in Arabidopsis thaliana
Authors: Zhong, Z., Bailey, M., Kim, Y.-I., Pesaran-Afsharyan, N., Parker, B., Arathoon, L., Li, X., Rundle, C. A., Behrens, A., Nedialkova, D. D., Slavov, G., Hassani-Pak, K., Lilley, K. S., Theodoulou, F. L., Mott, R.
The study combined long‑read whole‑genome assembly, multi‑omics profiling (DNA methylation, mRNA, ribosome‑associated transcripts, tRNA abundance, and protein levels) in two Arabidopsis thaliana accessions to evaluate how genomic information propagates through the Central Dogma. Codon usage in gene sequences emerged as the strongest predictor of both mRNA and protein abundance, while methylation, tRNA levels, and ribosome‑associated transcripts contributed little additional information under stable conditions.
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 reveals that a set of REPRODUCTIVE MERISTEM (REM) transcription factors, termed RIMs, are essential for directing RNA‑directed DNA methylation (RdDM) to CLSY3 targets in a sex‑specific manner in Arabidopsis reproductive tissues. Disruption of RIM DNA‑binding domains or their target motifs abolishes RdDM at these loci, demonstrating that genetic cues can guide de novo methylation patterns.
Arabidopsis REM transcription factors and GDE1 shape the DNA methylation landscape through the recruitment of RNA Polymerase IV transcription complexes.
Authors: Wu, Z., Xue, Y., Wang, S., Shih, Y.-H., Zhong, Z., Feng, S., Draper, J., Lu, A., Sha, J., Li, L., Wohlschlegel, J., Wu, K., Jacobsen, S. E.
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.