Genetius

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 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 uses a high‑throughput comparative multi‑omics strategy to profile transcript, metabolite, and protein dynamics in Arabidopsis thaliana seedlings throughout the heat‑stress memory (HSM) phase following acquired thermotolerance. Early recovery stages show rapid transcriptional activation of memory‑related genes, while protein levels stay elevated longer, and distinct metabolite patterns emerge, highlighting temporal layers of the memory process.

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.

The study introduces a CRISPR/Cas9‑based restoration system (CiRBS) that reactivates a disabled luciferase reporter (LUC40Ins26bp) in transgenic Arabidopsis, enabling long‑term single‑cell bioluminescence monitoring. Restoration occurs within 24 h after particle‑bombardment‑mediated CRISPR delivery, with ~7 % of cells regaining luminescence and most restored cells carrying a single correctly edited chromosome, facilitating reliable analysis of cellular gene‑expression heterogeneity.

The study demonstrates that N6‑methyladenosine (m6A) RNA methylation acts as a negative regulator of thermotolerance in Arabidopsis thaliana, with loss of m6A increasing heat‑responsive gene expression and mRNA stability. Heat shock triggers a transient reduction of m6A levels, which is linked to enrichment of the H3K4me3 histone mark at target loci, enhancing transcription of heat shock proteins. These findings reveal a coordinated interplay between RNA methylation and chromatin modifications that fine‑tunes the plant heat stress response.

The study examined how Arabidopsis thaliana integrates physiological, genetic, hormonal, and transcriptomic responses to combined water deficit, heat stress, and elevated CO2. Results show that stomatal aperture under these complex stress combinations is governed by a specific set of regulators, including nitric oxide, OPEN STOMATA 1, and the SLAH3 anion channel, distinct from those active under simpler stress conditions. This reveals a hierarchical stomatal stress code that could inform future research on plant resilience to global change.

The study demonstrates that constitutively active MLO (faNTA) can rescue the fer-4 root‑hair bursting and polarity defects, restoring tip‑focused cytosolic Ca2+ oscillations and ROS accumulation, highlighting a FERONIA‑MLO signaling module that governs Ca2+ influx and ROS production during root‑hair tip growth. Genetic analysis of mlo15-4 further confirms MLO15 as a key regulator of these Ca2+ and ROS dynamics. The findings suggest MLO proteins act downstream of FER to coordinate calcium and ROS signals essential for root‑hair integrity.

The study reveals that reactive oxygen species (ROS) have distinct temporal roles in Arabidopsis thaliana stigma papillae development, with superoxide promoting early growth and hydrogen peroxide marking mature, pollen‑receptive papillae. Pharmacological reduction of superoxide or transgenic over‑expression of superoxide dismutase under an early stigma promoter impairs papillae growth, highlighting ROS homeostasis as essential for proper papillae differentiation and successful pollination.

The study identifies HISTONE DEACETYLASE COMPLEX 1 (HDC1) as a positive regulator of sepal size during maturation in Arabidopsis thaliana, showing that hdc1 mutants exhibit prolonged elongation due to delayed maturation. Integrated transcriptomic and proteomic analyses, together with genetic and chemical experiments, reveal that HDC1 promotes ethylene production, which in turn triggers ROS accumulation to terminate sepal growth. These findings elucidate a coordinated ethylene‑ROS signaling mechanism controlling organ size during plant development.