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Context matters: coordinated transcriptional regulation and root plasticity under multinutrient conditions.

Plants often encounter simultaneous imbalances in multiple nutrients, but the regulatory logic coordinating their responses remains poorly understood. We aimed to uncover shared transcriptional programs and regulatory nodes underpinning multinutrient adaptation in Arabidopsis thaliana roots. We analyzed publicly available RNA-seq datasets spanning 15 nutrient and beneficial element conditions using differential expression, co-expression network (WGCNA), and gene regulatory network analysis. Selected transcription factors (TFs) were validated via root phenotyping, suberin staining, and ionomic profiling under two-nutrient stress conditions. We identified a core set of 2050 genes responsive to multiple nutrient treatments, enriched for suberin biosynthesis, and structured into modular co-expression clusters. Eight prioritized candidate TFs (ARR10, GBF3, HHO5, NAC32, NF-YA3, NF-YB2, SARD1, and WRKY33) were shown to modulate root system architecture under specific nutrient combinations. WRKY33 and NF-YB2, in particular, regulated nutrient-responsive suberin deposition and ionomic plasticity. These findings reveal suberin remodeling as a shared downstream process in multinutrient responses and suggest that plasticity is not a fixed trait but a modular, polygenic, and context-dependent outcome. Repurposed TFs with pleiotropic functions coordinate structural and physiological traits, providing regulatory entry points for improving nutrient resilience.

Plant Roots

ARR1 and ARR12 negatively regulate arsenic stress tolerance by controlling flavonoid metabolism in Arabidopsis.

ARR1/12-mediated cytokinin signaling negatively regulates the accumulation of glycosylated flavonoids, thereby increasing plant susceptibility to As(III) stress. Cytokinins negatively regulate arsenic stress tolerance in plants through cytokinin-signaling type-B Arabidopsis response regulators (B-ARRs), specifically ARR1 and ARR12. However, the mechanism by which cytokinin signaling regulates plant metabolite dynamics, particularly antioxidant flavonoids, in response to arsenic toxicity remains largely unknown. Here, we hypothesized that ARR1/12-mediated cytokinin signaling modulates flavonoid metabolism to regulate arsenite [As(III)] tolerance. By comparing the global metabolic changes in roots of the arr1 12 double mutant (rD) and wild-type (WT) plants, we found that As(III) stress globally reduced metabolite abundance in WT roots. Importantly, the rD mutant accumulated significantly more flavonoids, most in glycosylated forms, than WT under As(III) exposure, which was supported by the specific upregulation of UDP-glycosyltransferase genes involved in flavonoid glycosylation. Accordingly, exogenous application of the glycosylated quercitrin-enhanced As(III) tolerance in WT roots, strengthening that the increase of glycosylated flavonoids in rD roots was beneficial for plant survival under As(III) exposure. Our data collectively strongly support that the increased glycosylation of flavonoids in the rD mutant improves their antioxidant functionality, thereby enhancing the As(III) stress tolerance. This study provides a new insight into the negative role of cytokinin signaling in repressing glycosylated flavonoid accumulation, causing increased susceptibility of plants to As(III) stress. Manipulation of cytokinin signaling or flavonoid glycosylation is, therefore, a promising approach for heavy metal stress mitigation in crops.

Arabidopsis

Acetylcholine signaling regulates osmotic stress adaptation in the phytopathogen Dickeya solani.

Plants impose strong selective pressures that shape both the composition and functional potential of plant microbiomes. The adaptation of plant-associated bacteria to their hosts relies on an extensive repertoire of signal transduction systems that sense plant-derived molecules and dynamically adjust bacterial physiology and metabolism within the holobiont. These signals include key plant signaling compounds that regulate processes essential for plant-microbe interactions. Among them, acetylcholine is emerging as an important signaling molecule in both plants and bacteria. Here, we demonstrate that acetylcholine regulates the expression of the osmotic stress response betIBA gene cluster in the important phytopathogen Dickeya solani, where it plays an important role in osmoprotection. We show that the TetR-family transcriptional regulator associated with this pathway, BetIDs, recognizes acetylcholine as well as choline and trimethylamine. These three ligands differentially induce betIBA transcription in a manner that correlates with their binding affinities. Ligand binding does not affect BetIDs binding to the bet promoter or its oligomeric state. Instead, it induces pronounced changes in the secondary structure of BetIDs, with the magnitude of these conformational changes being ligand-dependent. We further show that quorum sensing modulates osmotic stress tolerance in D. solani by regulating the expression of the Bet pathway. The Bet system is required for the full virulence of D. solani, particularly in chemically complex plant tissues. Phylogenetic analyses reveal that the BetIBA system is widely distributed among plant-associated Pseudomonadota, collectively supporting its importance for bacterial survival and adaptation in plant-related environments.

Osmotic Pressure

Light regulates capsaicinoid biosynthesis via the CaHY5-CaBBX2-CaACS8 module in pepper.

Capsaicinoids are a class of unique alkaloids that confer the pungent taste to pepper fruits. However, it remains largely unknown how light regulates the biosynthesis of capsaicinoids. We conducted a metabolic analysis on light- and dark-adapted pepper fruits. The results showed that dark-adapted pepper fruits had lower capsaicinoid contents and correspondingly downregulated transcription of capsaicinoid biosynthetic genes (CBGs), indicating that light plays a crucial role in capsaicinoid biosynthesis. Furthermore, silencing of CaHY5, a pivotal transcription factor gene in the light signaling pathway, decreased the content of capsaicinoid and suppressed the expression of CBGs, whereas transient overexpression of CaHY5 generated exactly opposite results. CaHY5 can bind to the G-box motif in the promoters of CaBBX2 and CaACS8, thereby enhancing their transcriptional levels. The activated CaBBX2 then binds to the T/G-box in the CaACS8 promoter to stimulate its expression. CaBBX2 or CaACS8 silencing led to decreased levels of capsaicinoids, while their transient overexpression produced increased capsaicinoid contents. Collectively, our results indicated that the light-activated CaHY5-CaBBX2-CaACS8 regulatory module plays a pivotal role in capsaicinoid biosynthesis. These findings provide new insights into the influence of light on capsaicinoid biosynthesis and potential targets for activation of this biosynthetic pathway in pepper.

Capsicum

Developmental roles of LSD1/KDM1A-like (LDL) proteins in plants.

LYSINE-SPECIFIC DEMETHYLASE 1-like (LDL) proteins are conserved FAD-dependent amine oxidases that serve as pivotal regulators in plants. While animal systems typically rely on a single LSD1/KDM1A enzyme, the Arabidopsis thaliana genome encodes an expanded family of LDL homologues (FLD, LDL1, LDL2, and LDL3), resulting in substantial subfunctionalization and specialized recruitment mechanisms. This review explores the diverse developmental roles of plant LDLs, ranging from flowering time and circadian clock regulation to heterochromatin maintenance and epigenetic regulation. We discuss the redundant roles of FLD, LDL1, and LDL2 in repressing the floral repressor FLC and their nonredundant specialized function within the CCA1/LHY-TOC1 circadian feedback loop. A central focus of our review is the emerging mechanism of transcription-coupled demethylation, in which LDLs associate with the phosphorylated C-terminal domain of RNA polymerase II to modify chromatin cotranscriptionally within gene bodies. By integrating findings from Arabidopsis thaliana and crops such as tomato and soybean, we illustrate how the diversified LDL-mediated regulatory toolkit facilitates precise, gene-specific regulation. Ultimately, the LDL family represents a cornerstone of the sophisticated epigenetic strategies that regulate plant phenotypic plasticity in response to developmental and environmental cues.

Circadian clock

Complex evolutionary history of Rosales mediated by extensive incomplete lineage sorting and hybridization.

The angiosperm order Rosales still represents a major challenge for phylogenetic reconstruction. Although its circumscription is now well-defined, phylogenetic relationships among families are still uncertain. Here, we used nuclear, plastid, and mitochondrial genomic data from 33 species representing all nine families to further clarify interfamilial relationships and the group's evolutionary history. We detected significant phylogenetic conflict among the three datasets. Further analyses at the nuclear level identified incomplete lineage sorting (ILS) as the main cause of unstable phylogenetic positions among families. The discordant placements of Rhamnaceae and Elaeagnaceae based on plastid and mitochondrial data are caused by ancient hybridization events, potentially involving differences in organellar inheritance. Our molecular dating confirms earlier suggestions that the ancient rapid diversification of the three Rosaceae subfamilies could be the main reason for the difficulties in resolving their phylogenetic relationships. Our findings provide new insights into the interfamilial relationships of Rosales and demonstrate that the evolutionary history of this order was shaped by ancient and rapid radiation as well as extensive ILS and reticulate evolution. They also suggest that previous attempts to clarify interfamilial relationships in this order were hampered by combining nuclear and organellar sequence data, leading to inconsistent topologies observed across earlier studies.

Phylogeny

Integrated assessment of biocontrol potential and genome analysis of endophytic Bacillus velezensis MGL-B1 against mango stem-end rot.

Mango stem-end rot is a globally significant postharvest disease that severely threatens the mango industry, primarily caused by Botryosphaeria dothidea. However, information on biocontrol agents targeting this pathogen in mango remains limited. In this study, we isolated and identified a strain of Bacillus velezensis MGL-B1 from mango leaf tissues for the first time, which exhibited broad-spectrum antifungal activity. Both in vitro and in vivo assays demonstrated that MGL-B1 effectively inhibited the growth of B. dothidea, with an in vivo biocontrol efficacy reaching 83.72 ± 5.10%, comparable to that of the commonly used chemical fungicide thiabendazole. Further mechanistic analysis revealed that MGL-B1 acts by directly disrupting the integrity of the pathogen's mycelial cell membrane. In addition, its released volatile organic compounds (VOCs) also displayed significant antifungal activity, with components such as 2-nonanone, 2-nonanol, and phenylethyl alcohol being confirmed to exert antifungal effects in in vitro fumigation assays. qPCR analysis showed that MGL-B1 treatment significantly upregulated the transcriptional levels of genes involved in plant-pathogen interaction, phenylpropanoid biosynthesis, and antioxidant defense pathways in mango fruits, with upregulation folds of 16.32, 37.19, and 75.93, respectively; meanwhile, the expression of browning-related genes such as polyphenol oxidase (PPO) was markedly suppressed. Whole-genome sequencing further revealed 14 biosynthetic gene clusters for antimicrobial compounds, including five unknown gene clusters. Collectively, B. velezensis MGL-B1 represents a promising biocandidate strain with multiple antifungal mechanisms and excellent control efficacy, providing a valuable resource for green and sustainable management of mango diseases.

Mangifera

Phytolacca acinosa Roxb. induces intestinal toxicity through the histamine-MLCK-tight junction axis: Integrated evidence from proteomics, metabolomics, intestinal organoids and epithelial barrier validation.

Phytolacca acinosa Roxb. (PR) is a saponin-rich medicinal plant associated with gastrointestinal toxicity, but the mechanisms underlying PR-induced intestinal barrier injury remain unclear. In this study, raw PR extract was analytically characterized by UPLC-ZenoTOF-MS/MS, confirming triterpenoid saponins as the predominant constituents. C57BL/6 J mice were orally exposed to characterized PR extract (1.20 or 12.0 g/kg for 5 h), and Caco-2 cells and mouse intestinal organoids were used to assess epithelial toxicity and barrier disruption. Histopathology, ELISA, FITC-dextran permeability assays, immunofluorescence, CCK-8, LDH release, western blotting, DIA-based proteomics and untargeted metabolomics were integrated to define toxicological mechanisms. PR induced dose-dependent intestinal inflammation and barrier dysfunction, with the ileum as the most sensitive target. PR increased serum DAO and D-lactate and intestinal TNF-α and IL-1β, disrupted organoid morphology, enhanced epithelial permeability, and reduced ZO-1 expression. Proteomics revealed changes in inflammatory, lipid-metabolic, cytoskeletal and tight-junction pathways, including upregulation of MLCK3 and phospholipase-related proteins and downregulation of ZO-1 and ZO-2. Metabolomics identified histidine metabolism disturbance and histamine accumulation. Integrated multi-omics and pharmacological validation indicated that histamine activated the PLC/IP₃/Ca²⁺/CaM/MLCK cascade, promoting MLC phosphorylation, tight-junction disassembly and epithelial leakiness. MLCK inhibition partially restored ZO-1/ZO-2 expression and attenuated PR-induced epithelial injury. These findings identify the histamine-MLCK-tight junction axis as a key mechanism of PR-induced intestinal toxicity and support hazard identification of saponin-rich PR exposure.

Animals

Distinct cell morphotypes of Aureobasidium melanogenum ZN exhibit differential functional profiles in promoting maize growth.

Black yeast-like fungi of the genus Aureobasidium exhibit morphological plasticity, but whether distinct cellular states within the same genetic background are associated with different plant growth-promoting functions remains unclear. Here, yeast-like cells (YL), swollen cells (SC), and chlamydospores (CH) of Aureobasidium melanogenum ZN were characterized. YL was associated mainly with siderophore production and laccase activity, SC with extracellular polysaccharide accumulation, and CH with phosphate mobilization and higher ammonia and IAA production. Whole-genome and comparative genomic analyses revealed a shared repertoire related to nutrient acquisition, auxin-associated metabolism, extracellular oxidation, and carbohydrate remodeling, with expansions in nutrient- and cell-surface-related gene families. Transcriptomic and metabolomic analyses showed distinct deployment of these capacities, with CH exhibiting broad reprogramming of tryptophan-associated, nitrogen, phosphate, central-carbon, and amino-acid metabolism. In maize, CH at the optimal inoculation concentration of 105 CFU·mL-1 produced the strongest growth promotion, increasing plant height, dry biomass, root length, root surface area, and root volume by 58.6%, 365.1%, 191.0%, 194.3%, and 222.4%, respectively. Consistent with this pronounced growth phenotype, maize root transcriptomics showed coordinated CH-induced responses involving root development, nutrient transport, redox regulation, and root-interface remodeling. Root-zone tracking showed greater short-term stability and persistence of CH. These findings identify cellular state as an important functional dimension of Aureobasidium-plant interactions and provide a basis for developing fungal inoculants with defined beneficial cellular states.

Zea mays

Genome-Wide Characterization of β-Glucosidase (TaBGLU) Genes in Bread Wheat and Their Expression Under Drought, Cold, and Combined Stress.

Glycoside hydrolase 1 (GH1) β-glucosidases were known to activate hormone conjugates and defense metabolites, yet their genomic organization and stress-response dynamics in wheat remained incompletely defined. We therefore performed an integrated characterization of TaBGLUs spanning phylogeny, gene structure and conserved motifs, subcellular localization, promoter cis-elements, Gene Ontology enrichment, protein-protein interaction networks, and targeted expression profiling. Wheat TaBGLUs partitioned into well-supported clades that shared canonical GH1 catalytic residues and a largely conserved motif scaffold. Subcellular localization predictions indicated predominant nuclear and chloroplast targeting, with a smaller cohort directed to secretory or endomembrane compartments. Promoters were enriched for light-responsive, hormone-related (ABA, JA/SA, auxin, GA) and stress-associated (MYB/WRKY, heat, low temperature) cis-elements, and functional annotations were consistent with roles in carbohydrate and cell-wall metabolism, hormone homeostasis, and defense. Network analysis revealed a densely connected TaBGLU submodule embedded within broader carbohydrate and defense interaction networks, suggesting coordinated or cooperative functions. Expression profiling under cold, drought, and combined drought and cold demonstrated broad stress inducibility, with early activation detected by 6 h, cold-responsive maxima typically at 12 h, drought-responsive peaks predominating at 24 h, and combined stress eliciting both earlier and more sustained expression maxima between 12-24 h. Representative strongly responsive genes included TaBGLU20, TaBGLU44, TaBGLU6, and TaBGLU23, which showed pronounced late induction under combined stress, TaBGLU30, which exhibited an earlier combined-stress peak, and TaBGLU12, which displayed a marked late drought-specific response. Taken together, this integrated genomic, regulatory, and expression atlas refined the wheat BGLU repertoire relative to previous gene model inventories, highlighted candidate TaBGLUs with central network positions and strong stress inducibility, and provided concrete entry points for functional validation and breeding for improved stress resilience.

Triticum

Phosphorus modulates starch granule development and metabolic partitioning in wheat grain: Insights from SGAP proteomics and nutrition and processing quality.

This study investigates how phosphorus (P) levels are associated with carbon-nitrogen metabolism in wheat grains. Optimal P application (105 kg P₂O₅ ha⁻¹) was associated with enhanced pericarp-endosperm coordination, increased carbon allocation to the endosperm, and early B‑type starch granule formation. Starch granule‑associated protein (SGAP) proteomics showed that optimal P upregulated cytoskeletal and starch‑synthesis proteins bound to starch granules in the endosperm, while reducing storage protein degradation‑related SGAPs in the pericarp. These metabolic adjustments were correlated with increased grain‑filling intensity and duration, and were associated with the highest theoretical grain weight (50.70 mg). Furthermore, optimal P was associated with enrichment of amino acid biosynthesis pathways and with higher levels of essential amino acids (e.g., lysine and threonine by 17.0--26.8%) and an improved essential amino acid profile without altering total protein content. In contrast, excessive P (210 kg P₂O₅ ha⁻¹) was associated with disrupted inter‑tissue coordination but did not simply impair grain filling; instead, HP corresponded to a unique developmental program: it was linked to an early burst of C‑type starch granules (0∼5 µm) at 7 DPA, yet by maturity achieved the highest proportion of large A‑type granules (56.8%) and the highest total starch content (63.5%), together with elevated endosperm phosphorus at 14 DPA and enrichment of spliceosome‑related pathways. HP also showed higher levels of several functional amino acids (glutamate, cysteine, histidine, proline) compared to P0. However, HP was associated with a higher gliadin/globulin ratio and did not improve grain yield. These findings suggest that phosphorus supply is associated with grain quality through tissue‑specific metabolic reprogramming, and that precision management-rather than maximized application-warrants consideration for optimizing both yield and processing quality.

Triticum

Seed-derived mucilage polysaccharides as biomaterials for in vivo tissue regeneration: A systematic review.

Chronic wounds, bone defects, and cartilage injuries represent persistent clinical challenges requiring biomaterial platforms that actively regulate inflammation, oxidative stress, angiogenesis, and extracellular matrix remodeling. Conventional synthetic dressings often provide limited biological activity in these contexts. Seed-derived mucilages - polysaccharide-rich hydrocolloids obtained from chia (Salvia hispanica), flaxseed (Linum usitatissimum), fenugreek (Trigonella foenum-graecum), psyllium (Plantago ovata), guar (Cyamopsis tetragonoloba), quince (Cydonia oblonga) etc. - have emerged as biocompatible, biodegradable, and chemically versatile platforms for tissue engineering. This systematic review, conducted according to PRISMA 2020 guidelines, synthesized in vivo evidence on seed-derived mucilage-based biomaterials across wound healing, bone repair, cartilage regeneration, and related applications. PubMed, Scopus, and Web of Science Core Collection were searched for original in vivo experimental studies published in English between 2020 and 2026. Eligible studies reported at least one measurable regenerative outcome. Data were extracted independently by two reviewers, and methodological quality was assessed using the SYRCLE Risk of Bias tool. Forty-three studies were included. Hydrogels were the dominant biomaterial format, followed by films, scaffolds, sponges, nanoparticle systems, and bilayer or Janus composites. Included systems generally improved wound closure, re-epithelialization, collagen deposition, angiogenesis, antioxidant defense, and inflammatory regulation. However, most studies used small animals with short follow-up periods, and many incorporated nanoparticles or bioactive agents, limiting attribution of efficacy to the mucilage matrix alone. Risk of bias was predominantly unclear due to insufficient reporting of randomization and blinding. Blank mucilage controls, standardized characterization, long-term biosafety data, and clinically relevant models are essential prerequisites for translational progress.

Humans

Integrated metabolomic, transcriptomic, and proteomic analyses reveal changes in the non-volatile metabolite profile of LED light-withered oolong tea.

LED light withering is a crucial method for overcoming weather limitations and enhancing the quality of oolong tea. To elucidate the underlying molecular mechanisms, this study simulated solar spectra using multiwavelength LED light and compared the resulting metabolic, transcriptomic, and proteomic profiles during the enzymatic-catalysis process (ECP) in oolong tea processing. Results indicated that LED light withering altered gene expression and protein regulation of secondary metabolism, particularly in the flavonoid biosynthesis pathway. These shifts encompassed key quality-related compounds, including flavonoids (quercetin-3-O-rhamnoside, dihydroquercetin), amino acids (L-asparagine, L-histidine), guanosine 5'-monophosphate (GMP), and carbohydrates. Furthermore, LED light withering accelerated tea leaf water loss, influenced gene expression involved in photosynthetic cellular components (chloroplasts, thylakoids), increased ascorbate peroxidase regulation under stress, and subsequently modulated energy metabolism and signal transduction in tea leaves. This study offers molecular theoretical framework for the controlled light-withering of oolong tea under bad weather and the associated improvements in its quality.

Camellia sinensis

Ribosome stalling position, spacing, and A-site occupancy impact translation and cotranslational mRNA decay in plants.

Ribosomes can pause during mRNA translation, but what causes pausing, how pauses affect protein production, and whether they trigger cotranslational mRNA decay are poorly understood in plants. Here, we investigate the causes and consequences of ribosome pausing in Arabidopsis and maize. This is accomplished by sizing, mapping, and quantifying footprints of individual ribosomes (monosomes) and closely spaced ribosome pairs (disomes) at single-codon resolution on open reading frames (ORFs). Ribosome footprinting was combined with 5'P-degradome-seq to examine the coincidence of pausing with cotranslational decay under control conditions and brief hypoxia in Arabidopsis. The data resolve two monosome conformations and three disome configurations. These include monosomes with a vacant or occupied A-site and disomes that have collided or are separated by one or two codons. Pausing is prevalent at initiation, termination, and di-Proline codons. Di-Proline pauses do not trigger cotranslational decay but appear important in cotranslational protein processing. Brief hypoxia induces stalling of A-site vacant ribosomes at Aspartate codons, often coinciding with 5'P peaks, indicating that rate-limiting decoding can trigger cotranslational mRNA decay. Notably, actively transcribed and translated hypoxia-response mRNAs accumulate 1- to 2-codon-separated disomes and are actively degraded. Comparative analysis of footprints in the two species reveals ribosome conformations and codon-specific pausing can be conserved or lineage-specific, as exemplified by pausing at di-Prolines and on Conserved Peptide upstream ORFs. In sum, the stalling of ribosomes at specific codons, coupled with ribosome A-site occupancy and disome spacing, modulates protein production and cotranslational mRNA decay in plants.

Ribosomes

Pesticide occurrence, transformation, and transport from wastewater treatment plants into stream networks with diverse land uses.

Neonicotinoid insecticides and strobilurin fungicides are detected in many environmental compartments and have been associated with negative environmental and human health implications. Wastewater treatment plants (WWTPs) are often hotspots for introducing such contaminants into the environment. Therefore, the occurrence of strobilurin fungicides, neonicotinoids, and their metabolites at two WWTPs with varying land uses and population sizes was investigated. Polar organic chemical integrative samplers were deployed in WWTP influent and effluent and placed upstream and downstream of the effluent mixing zone for 2 weeks in April and July 2022. Biosolids were also collected at each time point. Neonicotinoids were detected with the highest frequency (68%), followed by strobilurin fungicides (49%) and neonicotinoid metabolites (31%). Time-weighted average concentrations for influent/effluent ranged from 85.2 ± 87.8 to 409.4 ± 74.5 ng/L. Pesticide concentrations, specifically the metabolites, typically increased from influent to effluent, resulting in effluent having higher pesticide loads than influent. Pesticide concentrations varied between the upstream and downstream monitoring locations by analyte, with WWTP samples in the highly developed region having significantly higher concentrations of pesticides and less variation by monitoring period. Chronic ecotoxicity benchmarks for freshwater invertebrates for imidacloprid were surpassed in treated effluent at both WWTPs in July and in the downstream monitoring location in the heavily developed area. Findings support the need for further exploration of pesticide contributions from WWTPs to river systems, specifically related to metabolite contributions to downstream streams and their effects on aquatic environments.

Water Pollutants, Chemical

Free polyphenols and multi-omics traits underlying antioxidant variation across Paeonia lactiflora leaf cultivars.

Leaves of Paeonia lactiflora are underutilized by-products with potential as natural antioxidant sources. In this study, 18 cultivars were evaluated for phytochemical composition and in vitro antioxidant capacity. Total phenolic content correlated strongly with DPPH and ABTS activities, and the comprehensive antioxidant index identified 'Coral Charm' and 'Hangshao' as representative high- and low-antioxidant cultivars, respectively. Untargeted metabolomics detected 2677 metabolites and identified 908 differential metabolites between the two cultivars. Targeted phenolic profiling quantified 27 compounds, among which 11 differed significantly between the two cultivars. Catechin and epicatechin were enriched in 'Coral Charm', with contents of 6.62 and 0.397 ng/mg, respectively, compared with 0.012 and 0.002 ng/mg in 'Hangshao'. (+)-Dihydroquercetin was also more abundant in 'Coral Charm', while caffeic acid showed an upward trend. Proteomic analysis identified 423 differentially expressed proteins, mainly associated with secondary metabolite biosynthesis, redox homeostasis, and central carbon metabolism. Integrated analysis identified pyruvate metabolism as the only pathway significantly enriched in both metabolomic and proteomic datasets. Molecular docking predicted favorable binding between representative phenolics and selected proteins. These findings link cultivar-dependent antioxidant variation in peony leaves with free-phenolic accumulation and pathway-level metabolic differences, supporting the selection and utilization of antioxidant-rich peony leaf resources.

Antioxidants

The cold case of state transition 7 (stt7) mutants of Chlamydomonas reinhardtii, solved by whole-genome sequencing.

The process of State Transitions (ST) corresponds to an STT7 kinase-driven redistribution of the transmembrane LHCII antenna proteins between Photosystem II (PSII) and Photosystem I (PSI), which results from changes in their phosphorylation state. For the past two decades, two LHCII-kinase mutants, stt7-1 and stt7-9, have been instrumental in the study of STs in Chlamydomonas reinhardtii, the former being a null mutant for the kinase but quasi-sterile in crosses, while the latter, although fertile, has a leaky phenotype. Using long-read sequencing, this study further characterized the genetic lesions of the stt7 mutant strains through whole-genome reconstruction and de novo chromosome assembly. In addition, two new stt7 null mutants were generated, one derived by crosses from the original stt7-1 and one obtained by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated protein 9 (Cas9) technology. This work provides a comprehensive genomic characterization of the original stt7-1 null mutant, revealing extensive chromosomal rearrangements and high levels of aneuploidy, associated with increased cell size and meiotic dysfunction. Reassessment of their physiology and genetic backgrounds highlights the need for caution in interpreting genetic information. We thus produced more reliable null mutants for the LHCII-kinase, amenable to genetic crosses for the study of STs in a variety of genetic backgrounds.

Chlamydomonas reinhardtii