Genetius

The study examined five sequential organ abscission events in two cherry species, revealing that some abscission zones form de novo while others are pre‑formed and reactivated by localized ethylene signaling, leading to cell division, lignification, ROS accumulation, and pH changes. Species‑specific differences were found in petal shedding and a post‑fertilization checkpoint that eliminates small fruits, indicating a hierarchical, multilayered reproductive filter controlling fruit set.

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.

The study demonstrates that Candidatus Liberibacter asiaticus induces reactive oxygen species production in chloroplasts and phloem callose deposition, leading to cell death and Huanglongbing (HLB) symptoms in citrus. Genetic manipulation—overexpressing chloroplast flavodoxin to reduce ROS, and editing callose synthase genes—along with chemical inhibition of callose formation, mitigates disease severity, while tomato‑Lpsy infection models reveal key immune regulators (Eds1, Pad4) required for these responses. These findings provide genetic evidence for a CLas‑triggered immune disease and suggest precision breeding strategies for HLB resistance.

The chickpea-derived cysteine‑rich peptide NCR13_PFV1 exhibited nanomolar antifungal activity against both QoI‑sensitive and -resistant isolates of the soybean pathogen Cercospora sojina, protecting sprayed soybean leaves without phytotoxicity and showing additive effects with azoxystrobin. The peptide disrupts fungal plasma membranes, induces ROS, is rapidly internalized, binds fungal rRNA, and inhibits protein translation, with iron availability modulating its activity. These multifaceted mechanisms suggest NCR13_PFV1 as a promising bio‑fungicide for durable FLS management.

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 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 researchers used the Pseudomonas syringae pv. tomato DC3000 polymutant D36E, which lacks 36 known T3SS effectors, as a non‑pathogenic delivery platform to introduce individual effectors into spinach and assess their impact on disease symptoms, bacterial growth, and early ROS‑mediated immunity. High‑throughput screening of 28 DC3000 effectors identified AvrE1 and HopM1 as drivers of water‑soaked lesions, whereas HopAD1 markedly suppressed ROS bursts, establishing D36E as a versatile tool for functional effector studies in spinach.

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.

The study demonstrates that dihydroxy B‑ring flavonoids modulate the amplitude of the core circadian clock gene reporter TOC1:LUC in Arabidopsis by affecting cellular H2O2 levels, rather than auxin transport. Reducing reactive oxygen species restored normal TOC1:LUC amplitude in flavonoid‑deficient seedlings, and altered chloroplast Ca2+ levels suggest a retrograde signaling component.