Genetius

A comparative phosphoproteomics study using Arabidopsis thaliana ahk5 loss‑of‑function mutants and wild‑type seedlings revealed that the histidine kinase AHK5 mediates a rapid shift from multistep phosphorelay signaling to serine/threonine phosphorylation in response to H2O2. AHK5 controls ROS‑responsive phosphorylation of plasma‑membrane nanodomain proteins and orchestrates distinct ABA‑independent stomatal closure and ABA‑dependent root development pathways by modulating key components such as RBOHD, CAS, HPCA1, and auxin transporters.

The study uses an optogenetic ChannelRhodopsin 2 variant (XXM2.0) to generate defined cytosolic Ca²⁺ transients in Arabidopsis root cells, revealing that these Ca²⁺ signatures suppress auxin‑induced membrane depolarization, Ca²⁺ spikes, and auxin‑responsive transcription, leading to reversible inhibition of cell division and elongation. This demonstrates that optogenetically imposed Ca²⁺ signals act as dynamic regulators of auxin sensitivity in roots.

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 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.

The study resolves the ectodomain structure of the plant-specific LRR‑RLK CARD1 (HPCA1) and reveals a surface‑exposed copper ion coordinated by histidines that is essential for hydrogen peroxide signaling. Combined structural, genetic, and biochemical analyses show that previously identified cysteine residues are not required for signal perception, establishing CARD1 as the first copper‑dependent redox receptor.

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 reveals that the endoplasmic reticulum‑associated degradation (ERAD) pathway governs the proteasome‑dependent turnover of PIN‑LIKES (PILS) auxin transport proteins under normal conditions, and that both internal and external cues modulate this process via the ERAD complex. These findings link ER protein homeostasis to auxin‑mediated growth regulation, highlighting a new mechanism by which plants adapt to environmental and developmental signals.

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.

The study reconstitutes Papaver rhoeas self‑incompatibility (SI) in Arabidopsis thaliana by expressing the pollen S‑determinant PrpS, revealing that SI triggers a rapid Ca2+‑dependent signaling cascade that leads to mitochondrial H2O2 production, metabolic collapse, and programmed cell death. Using a genetically encoded H2O2 sensor and metabolic assays, the authors show that early mitochondrial disruption, driven by altered Ca2+, cytosolic pH, and distinct ROS sources, is central to the SI response.

The study compared two plasma‑activated water (PAW) solutions with different H₂O₂ levels, produced by a radio‑frequency glow discharge, on Arabidopsis thaliana growth and stress responses. PAW lacking detectable H₂O₂ promoted seedling growth and induced nitrogen‑assimilation genes, while H₂O₂‑containing PAW did not affect growth but enhanced root performance under heat stress; mature plants fertilized with H₂O₂‑free PAW performed comparably to nitrate controls. These results indicate PAW can replace NO₃⁻ fertilizers provided H₂O₂ levels are carefully managed.