Search Results (3,468)

To elucidate how roots respond to hydroponics, we investigated the mechanisms by which nutrient solution flow influences root growth in hydroponic lettuce via phenotypic analysis combined with single-cell RNA sequencing. Nutrient solution flow exerted a dual-phase effect on lettuce root growth, characterized by initial inhibition followed by subsequent promotion. Although initially, root biomass and morphological indices were significantly lower under flow treatment than under static treatment, this trend rapidly reversed by days 2 and 3 and all the measured indices showed improved root growth under flow treatment. Single-cell transcriptomic analysis enabled the construction of a comprehensive cellular atlas of hydroponic lettuce roots, which indicated heterogeneous transcriptional responses for lettuce roots under static and flow treatments. Flow treatment altered root cell composition, inducing decreases in initial cells and increases in vascular cells. Pseudotime trajectory analysis suggested that the differentiation of initial cells into vascular tissues was associated with plant hormone signaling and MAPK pathway-related gene expression, and also revealed differential expression of key functional genes, including ACO3 in root cap cells and CAM7 in xylem cells. Therefore, this study provides insights into the transcriptional regulatory framework of hydroponic lettuce roots in response to nutrient solution flow, which may provide a basis for optimizing hydroponic crop production via rhizosphere environment regulation. Full article

Brackish water irrigation induces secondary soil salinization and severe nitrogen (N) leaching, restricting crop N uptake and grain yield. To address these constraints in coastal saline farmlands, a 140-day field soil column experiment was conducted using coastal saline soil with a salinity of 2.60 g kg⁻¹. We evaluated the individual and interactive effects of three straw return methods (straw removal (S1), straw incorporation (S2), and straw burial (S3)) and three N fertilizer managements (sole conventional urea (N1), 1:1 mixture of polyurethane-coated urea (PCU) and urea (N2), and sole PCU (N3)) on salt dynamics, rice agronomic traits, root morphological characteristics, N use efficiency (NUE), and yield components. The results indicated no significant interactive effects between straw return methods and N fertilizer managements on the measured variables (p > 0.05). S2 significantly decreased soil salinity and exerted the highest efficiency with regard to salt leaching, thereby promoting rice growth (p < 0.05). PCU markedly optimized root development, as evidenced by increased root tip number, branch number, and root crossing density (p < 0.05), which strengthened water and nutrient uptake, ultimately mitigating detrimental impacts of brackish water irrigation on grain yield and NUE. Notably, PCU application ratios showed no significant differences in crop yield (p > 0.05). Overall, straw incorporation combined with a 1:1 ratio of PCU and urea is verified as the optimal strategy for rice cultivation in brackish water-irrigated coastal saline regions. This practice effectively alleviates brackish water-induced salt stress and elevates crop yield and NUE. The outcomes provide solid scientific references and practical guidance for coordinated water–salt–nutrient management and sustainable utilization of fragile coastal saline soils. Full article

Arbuscular mycorrhizal fungi (AMF) establish a reciprocal interaction with plant roots, enhancing nutrient acquisition, stress tolerance, and the production of bioactive metabolites. These symbiotic fungi represent a sustainable alternative to chemical fertilizers to improve the quality and yield of medicinal and aromatic plants such as Oregano (Origanum compactum). In this study, we investigated the effects of mycorrhizal inoculation on the chemical composition, nutritional profile, and biological activities of Oregano cultivated under greenhouse conditions. Compared with non-mycorrhizal plants, mycorrhizal-inoculated plants showed approximately 33% higher protein content and 28% higher total sugar content, while lipid concentration decreased slightly by about 7%. Mycorrhizal inoculation also promoted the accumulation of secondary metabolites, resulting in increased concentrations of total polyphenol and flavonoid contents by approximately 33% and 25%, respectively. These compositional changes were associated with markedly enhanced antioxidant capacity, exceeding that of the reference antioxidant, as well as improved antibacterial activity, characterized by larger inhibition zones and lower minimum inhibitory concentrations against tested pathogens. Overall, mycorrhizal fungal inoculation reshaped the chemical composition and the major bioactive compounds of Oregano, thereby enhancing its nutritional and antimicrobial potential. These findings highlight the potential of AMF-based cultivation strategies to improve the phytochemical quality and medicinal potential of Oregano while supporting sustainable agricultural production. Full article

Solanum rostratum is an invasive plant species that poses a serious threat to native ecosystems. In this study, we investigated S. rostratum populations in saline-alkali regions of western Jilin Province to characterize root-associated arbuscular mycorrhizal (AM) fungal diversity and evaluate the effects of AM fungi on plant growth and competitive ability. The results showed that S. rostratum roots were widely colonized by AM fungi, indicating abundant AM fungal resources in its rhizosphere. High-throughput sequencing identified 45 AM fungal species belonging to 13 genera, with Glomus as the dominant genus. A compartmented mesh pot experiment further demonstrated that AM fungal inoculation significantly enhanced the growth and photosynthetic performance of S. rostratum, particularly under saline-alkali soil conditions. When AM fungi were inoculated only in the compartment containing the native plant Setaria viridis, AM fungal colonization was also detected in S. rostratum roots, indicating hyphal connections between neighboring plants through the mesh barrier. Stable isotope analysis further revealed that AM fungi facilitated nitrogen acquisition by S. rostratum and increased ¹⁵N transfer from neighboring S. viridis under common mycorrhizal networks. These findings suggest that abundant AM fungal resources in the rhizosphere contribute to the growth advantage of S. rostratum. By enhancing nutrient acquisition and potentially facilitating nitrogen transfer through mycorrhizal networks, AM fungi may strengthen the competitive ability of this invasive plant under saline-alkali conditions. Full article

The rhizosphere microbiome is critical for plant health, yet how soil type and intensive management jointly govern its assembly remain unclear. Here, we hypothesized that soil type acts as a primary environmental filter, while intensive cultivation (plant growth plus fertilization) imposes additional selective pressures that differentially shape bacterial versus fungal communities. Using flue-cured tobacco (K326) grown in clay loam and sandy loam soils under field conditions, we examined the rhizosphere microbiome at the topping stage. Intensive cultivation significantly altered rhizosphere physicochemical properties. Key nutrients, including organic matter (OM), dissolved total nitrogen (DTN), available phosphorus (AP), and available potassium (AK), were markedly enriched. Rhizosphere soil pH exhibited a bidirectional shift relative to the corresponding bulk soil, converging to a narrow range (7.4–7.8) in both soil types. Root activity and fertilization imposed contrasting selective pressures on the two microbial kingdoms: bacterial diversity declined slightly, indicating strong deterministic selection, whereas fungal diversity increased, reflecting adaptation to root-generated niches. Differential abundance analysis identified 38 bacterial OTUs as a core rhizosphere-adapted microbiome shared across both soil types, demonstrating robust fitness in the nutrient-enriched rhizosphere environment under intensive management. No shared core fungal OTUs were detected, underscoring strong soil legacy effects and higher habitat specificity in fungi. Notably, the core bacterial microbiome was dominated by K-strategists (slow-growing, resource-efficient taxa) that exhibited opportunistic traits capable of rapidly exploiting nutrient pulses in the rhizosphere. Together, these findings reveal that soil type acts as a critical filter modulating plant–microbe interactions under intensive agriculture, while bacteria and fungi employ divergent ecological strategies in response to selection pressures. This work provides both theoretical and practical insights for optimizing tobacco cultivation and sustaining soil microecological health. Full article

Plateau environments are characterized by low temperatures, intensive radiation and drastic diurnal temperature fluctuations, all of which greatly suppress rooting and seedling establishment of tea chrysanthemum cuttings. To compare the regulatory effects of different rooting regulators on tea chrysanthemum cuttings under plateau cultivation conditions, this study conducted a 60-day plug-tray cultivation experiment from late July to late September with three biological replicates. All the cuttings, including the IBA-pre-treated control (CK), were uniformly pretreated with 500 mg·L⁻¹ indole-3-butyric acid (IBA). On this basis, four treatments, including 5-aminolevulinic acid hydrochloride (5-ALA, T1), γ-aminobutyric acid (GABA, T2), Bacillus amyloliquefaciens (T3) and Bacillus velezensis (T4), were applied to determine root morphology, seedling growth, physiological stress metabolism, photosynthetic capacity and rhizosphere substrate characteristics. The different rooting promoters exerted distinct regulatory effects on cutting performance. The GABA treatment significantly improved leaf gas exchange, seedling growth, antioxidant status and rhizosphere nutrient conditions, with net photosynthetic rate, stomatal conductance and transpiration rate improved by 316.34%, 92.31% and 168.00%, respectively, and significantly increased seedling vigor index, plant height and stem diameter by 21.74%, 60.85% and 46.08%, respectively. It also elevated the soluble sugar content and the ascorbate peroxidase (APX) activity, reduced malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) accumulation, and optimized rhizosphere available nitrogen and phosphorus levels, as well as related enzyme activities. Nevertheless, the 5-ALA treatment exhibited unique advantages in improving rooting rate and seedling survival. Mantel tests confirmed that the seedling vigor index closely correlated with the root architecture, the total chlorophyll and the transpiration rate. A principal component analysis (PCA) and a cluster heatmap both identified GABA as the treatment with relatively balanced overall performance. A comprehensive D-value evaluation ranked the treatments as GABA > B. amyloliquefaciens > 5-ALA > B. velezensis > control. The treatment with 5-ALA mainly improved the antioxidant capacity, the B. amyloliquefaciens treatment favored root elongation and total nutrients, and the B. velezensis treatment only produced mild improvements. This study indicates that the different exogenous regulators target divergent growth and physiological processes, and the GABA treatment could coordinately boost root development, photosynthetic performance, antioxidant defense and rhizosphere nutrient cycling, thus presenting great application potential for tea chrysanthemum cutting propagation under plateau cultivation conditions. Full article

The degradation of Calcisols in the arid regions of Central Asia constrains sustainable agricultural production because of low organic matter content, poor aggregate stability, nutrient limitations, and increasing climatic stress. This study evaluated a rhizosphere engineering approach based on the native plant growth-promoting bacterium Pseudomonas veronii Ps-S/Sh-1503/2022 for the rehabilitation of degraded Calcisols. Four-year field experiments (2022–2025) using Sorghum bicolor assessed plant growth, rhizosphere microbial indicators, physiological responses, pathogen suppression, crop productivity, and implementation feasibility through economic and environmental assessments. Inoculation with P. veronii increased root depth by 45%, improved aboveground biomass, increased the ratio of culturable bacteria to Fusarium spp. from 6.1 to 10.3, and reduced Fusarium abundance by 29.4%. Structural equation modeling suggested that trophic support (42.1%), aggregate stabilization (27.4%), biocontrol (23.3%), and defense-related responses (7.2%) were the principal pathways associated with soil rehabilitation. Economic assessment indicated that the combined inoculation and mineral fertilization treatment provided the highest profitability, while environmental assessment estimated potential reductions in mineral fertilizer use and greenhouse gas emissions. These findings suggest that rhizosphere engineering using a native P. veronii strain represents a promising, economically viable, and climate-smart approach for improving the biological functioning of degraded Calcisols and supporting sustainable agricultural production. Full article

In protected cultivation, light intensity, spectral quality, red/far-red ratio, photoperiod and diel fluctuation can alter the belowground biological environment by modifying carbon allocation, root architecture, root exudation, nutrient acquisition, immune tone and rhizosphere physicochemistry. Direct community-level evidence in vegetables remains sparse, but targeted experiments on bacterial colonization, arbuscular mycorrhizal symbiosis, beneficial fungi and root pathogens show that light can condition specific plant–microbe interactions. This review develops a molecular framework for light–root–microbiome interactions in protected vegetable crops and distinguishes direct community evidence, targeted colonization or symbiosis evidence, crop-specific indirect evidence and mechanistic analogues. We synthesize how photoreceptors and PIF-, HY5-, hormone- and immunity-related pathways regulate root niche construction, while also considering direct microbial photoreception. Experimental examples include tomato rhizosphere responses to shading, R:FR-dependent colonization by Serratia plymuthica, phyB–HY5–strigolactone control of tomato mycorrhization, light-intensity effects on lettuce–AMF interactions, spectrum-dependent Trichoderma harzianum colonization and light sensing by Ralstonia pseudosolanacearum. The evidence supports the view that light acts as a conditional regulator whose effects depend on crop genotype, microbial partner, substrate, nutrient status and developmental stage. Progress will require factorial lighting experiments coupled with exudomics, stable-isotope tracing, absolute microbial quantification, isolate genomics, synthetic communities and pathogen-challenge assays. Full article

Understanding the dynamics of carbon (C), nitrogen (N), and phosphorus (P) stoichiometry and C stocks along a stand development chronosequence has been extensively studied in forest ecosystems. However, despite the global economic and ecological importance of apple orchards, such knowledge remains limited for these intensively managed perennial agroecosystems. We examined C, N, and P concentrations and stoichiometric ratios in tree tissues (root, stem, branch, foliage) and soils (0–100 cm depth), as well as ecosystem C stocks, across a chronosequence of 4, 8, 12, and 16 yr old Malus pumila orchards in the eastern Yan Mountains, Hebei Province, North China. The results showed that C concentrations exhibited no consistent age-dependent trend in tree tissues. In contrast, N and P concentrations in all tree tissues decreased significantly with stand age, while their C:N and C:P ratios increased. The leaf N:P ratios suggested progressive P limitation as orchards aged. In soil, C, N, and P concentrations first decreased and then increased along the chronosequence, with the highest values observed in the 16 yr stands. This U-shaped trajectory reflected the dynamic interplay between stand development and anthropogenic management. Intercropping and intensive fertilization in the 4 yr orchards initially elevated soil nutrient levels, while the cessation of intercropping and nutrient removal via fruit harvesting in the 8 yr stands led to a decline. Thereafter, accumulation of litter decomposition and root turnover, combined with continued organic matter inputs, progressively replenished soil nutrient pools in the 12 and 16 yr stands. The total ecosystem C stocks ranged from 70.80 to 136.13 Mg ha⁻¹, initially declining from 4 to 8 years and then increasing at 12 and 16 years, with soil contributing 84.7–99.7% of the total. Plant and soil nutrient concentrations showed predominantly negative correlations, indicating weak coupling between tree and soil nutrient pools. Our findings demonstrated that stand age profoundly influenced C:N:P stoichiometry and C stocks in apple orchard ecosystems and that prolonged orchard development enhanced both tree biomass C and soil C stocks. These results provide a scientific basis for nutrient optimization and sustainable management of apple orchards in temperate regions. Full article

The rising global food demand requires boosting agricultural productivity without compromising environmental sustainability, especially in the face of intensive agrochemical use and soil degradation. Based on this, strain TRQ67 was isolated from wheat rhizosphere soil in the Yaqui Valley, Mexico, and characterized morphologically, biochemically, and genomically. Strain TRQ67 possesses a genome of 4.04 Mbp across 37 contigs with a G + C content of 46.3%, comprising 4127 coding DNA sequences (CDSs), and was identified as Bacillus velezensis through Overall Genome Relatedness Indices (OGRIs), including Average Nucleotide Identity (OrthoANI = 99.12%) and Genome-to-Genome Distance Calculator (Formula 2: 92.6%). The genome revealed key functional genes associated with auxin biosynthesis (trpABCDEF and yhcX), iron acquisition (dhbABF), nutrient solubilization (gabD, acnAB and pyc), stress response (clpCEPX and pspA), antifungal metabolite synthesis (srfAABCD, fenABCD and bmyABC), chemotaxis and motility (cheABCD, motAB, flgBCDEF, swrC), bacterial fitness (acoABR, acuABC and budABC), exopolysaccharide production (epsDEFHI), sporulation (spo0ABEF) and bioremediation. Predicted gene functions were supported by in vitro phenotypic assays; strain TRQ67 was able to solubilize phosphate (Solubilization Index of 4.1 ± 0.46), biosynthesize siderophores (Production Index of 1.70 ± 0.16), and produce indoles (6.52 ± 0.63 µg mL⁻¹). Furthermore, this strain demonstrated antagonistic activity against phytopathogenic fungi Fusarium languescens and Bipolaris sorokiniana, resulting in reductions in fungal growth area of 87.33% and 89.28%, respectively. These antagonistic effects are consistent with the presence of Biosynthetic Gene Clusters (BGCs) encoding lipopeptides (surfactin and fengycin), polyketides (difficidin, bacillaene and macrolactin H), dipeptides (bacilysin) and siderophores (bacillibactin), as identified through antiSMASH analysis. Finally, the strain significantly improved root (27.63%) and shoot (5.82%) biomass in wheat plants under controlled conditions. These results highlight Bacillus velezensis TRQ67 as a promising microbial inoculant with plant growth promotion capabilities and potential antifungal activity against phytopathogenic fungi, as evidenced by strong in vitro antagonistic activity, supporting its further evaluation for sustainable agricultural practices. Full article

Lingonberry (Vaccinium vitis-idaea L.) has a weak root system and limited nutrient acquisition capacity. Plant growth-promoting rhizobacteria (PGPR) can promote plant growth by regulating rhizosphere nutrient cycling and host metabolism, but the underlying mechanisms in Ericaceae remain unclear. In this study, the strain Microbacterium sp. Y107 was isolated from the rhizosphere of lingonberry. Using growth-promoting assays (with 9 independent biological replicates, each consisting of 3 plants per bottle as the experimental unit, an inoculum density of OD₆₀₀ = 1.0, a cultivation period of 60 days, and whole-plant harvesting), GC–MS-based metabolite analysis, axenic coculture, analyses of the rhizosphere environment and gene expression, transcriptome sequencing (3 biological replicates per treatment), and qRT–PCR validation, we systematically evaluated the effects of strain Y107 on lingonberry growth, rhizosphere conditions, and host gene expression. CK (control) plants were defined as those inoculated with sterile LB liquid medium. Pearson correlation analysis was also used to assess the relationships among plant growth, soil traits, and physiological indices. Compared with the CK treatment, strain Y107 significantly promoted lingonberry growth (p < 0.05), increasing the fresh weight of the roots by 157.65% and the whole-plant fresh weight by 33.85%, respectively, and increasing peroxidase (POD) activity by 61.11%, while reducing the contents of reducing sugars and proline. Strain Y107 stably colonized the lingonberry root surface and formed biofilms. Y107 treatment resulted in detectable levels of soil microbial biomass carbon and nitrogen, indicating successful microbial colonization. The ammonium nitrogen content significantly increased, increasing nitrogen availability and promoting root nutrient uptake. Transcriptome analysis revealed that the expression of genes enriched in photosynthesis-related pathways, as well as those involved in carbon and nitrogen metabolism and redox regulation, was altered in strain Y107, which upregulated key photosynthesis-related genes such as psbP and ndhU and significantly enriched the cytosolic ribosomal large subunit gene set in a negative direction. Correlation analysis further revealed that strain Y107 optimized the association between lingonberry growth and soil nutrients. Overall, strain Y107 promoted lingonberry growth through stable colonization, enhanced nutrient cycling, promoted lingonberry growth, and altered the expression patterns of genes involved in photosynthesis-related pathways. Full article

Coastal sandy ecosystems face compounded abiotic stresses, including nutrient-poor soils, strong winds, and salt spray, making vegetation restoration highly challenging. Plant functional traits are key indicators of adaptive strategies under environmental stress, yet systematic studies on leaf, twig, and root functional traits of bamboo stands under different silvicultural regimes in coastal sandy land remain scarce. This study examined six stand types on Dongshan Island, Fujian Province: monospecific stands of Bambusa oldhamii Munro, Phyllostachys nidularia f. farcata Wen, and Bambusa tuldoides ‘Swolleninternode’, and their corresponding mixed stands with Casuarina equisetifolia L. (bamboo-to-C. equisetifolia ratio 7:3). Eighteen morphological and structural indices spanning three organ categories, leaf morphology (leaf area, specific leaf area [SLA], leaf tissue density [LTD], etc.), twig structure (wood density, dry matter content, etc.), and root morphology (specific root length [SRL], specific root surface area [SRA], root tissue density [RTD], etc.), were measured and analysed using Pearson correlation and principal component analysis (PCA). Results: (1) Coefficients of variation (CV) for leaf and twig traits ranged from 11.29% to 74.61%; leaf area (CV = 74.61%) and twig wood density (CV = 71.91%) were most variable, indicating high phenotypic plasticity of bamboo in coastal sandy environments. (2) Twig wood density in monospecific stands of B. oldhamii (0.346 g cm⁻³) was significantly higher than in all other stands (p < 0.05), reflecting a conservative water-transport strategy; mixed stands of B. oldhamii had significantly higher SRL and SRA than other stands (p < 0.05), indicating stronger root resource-acquisition capacity. (3) PCA revealed that leaf area, leaf volume, SLA, LTD, SRL, average root diameter, total root volume, total root surface area, and twig wood density (TWD) were the key traits distinguishing stands under different silvicultural regimes; monospecific stands scored higher overall than mixed stands, reflecting superior leaf, twig, and root functional coordination. Different silvicultural regimes significantly shape the functional adaptive strategies of bamboo in coastal sandy land. Bamboo plants integrate leaf, twig, and root traits in a coordinated, resource-conservative manner to withstand coastal stresses. These findings provide a theoretical basis for bamboo species selection and mixed-stand configuration in coastal shelterbelt management. Full article

Climate change is increasing the frequency and severity of abiotic stresses, including salinity, drought, heat, and heavy metal toxicity, which strongly threaten productivity, quality, and market value in horticultural crops. Although plant biostimulants have been widely reviewed in agronomic crops, their role in horticultural systems remains less comprehensively synthesized, particularly across different crop groups, stress types, application methods, and molecular response mechanisms. This review addresses this gap by systematically compiling current evidence on the use of biostimulants to improve abiotic stress resilience in horticultural crops, with particular emphasis on morphological, physiological, biochemical, and recently emerging molecular responses, especially transcriptomic evidence with supporting metabolomic information where available. Publications were retrieved from the Web of Science Core Collection using two searches covering 2016–2025 for morphological/physiological responses and 2021–2025 for molecular/genetic responses. Of 780 records initially identified, 134 studies met the inclusion criteria. Across these studies, the most frequently evaluated biostimulants were seaweed extracts, humic and fulvic substances, protein hydrolysates, and microbial inoculants, particularly PGPR and AMF. Biostimulant application consistently improved stress tolerance by enhancing antioxidant capacity, osmotic adjustment, nutrient use efficiency, cell wall strengthening, and hormonal regulation. Foliar applications were frequently used for rapid mitigation of drought- and heat-induced canopy-level physiological responses, whereas soil/root-zone application was more common for salinity and heavy metal stress. Emerging molecular evidence, dominated by transcriptomic studies and supported by limited metabolomic data, indicates that biostimulants may induce molecular priming through stress-responsive gene networks and associated metabolic adjustments. Overall, biostimulants show strong potential to improve abiotic stress resilience in horticultural crops, but broader adoption is constrained by variable efficacy, limited mechanistic validation, and inconsistent regulatory frameworks. Future research should prioritize multi-environment validation and functional genetics to support more reliable and targeted biostimulant use. Full article

To ensure large-scale production of plant-derived polyphenols, efficient and scalable in vitro culture systems are needed that can enable high biomass accumulation and secondary metabolite biosynthesis. The present study evaluates the suitability of transformed Salvia bulleyana shoot and hairy root cultures for biomass growth and phenolic compound production in different bioreactor systems, including two temporary immersion systems (PlantForm™ and RITA^®) and a nutrient sprinkle bioreactor (NSB). A pronounced system- and organ-specific response was observed. In transformed shoot cultures, the RITA^® bioreactor promoted high growth and volumetric productivity, although metabolite accumulation was lowered by partial hyperhydricity. In contrast, the PlantForm™ system provided more stable morphogenesis and higher polyphenol content, although less effective growth. In hairy root cultures, the NSB proved to be the most effective system, combining high biomass productivity with greater phenolic compound accumulation; total polyphenol content reached 65.1 mg/g DW, with rosmarinic acid (RA) constituting up to 78% of total phenolics. The highest volumetric productivity was achieved in NSB-grown hairy roots, reaching 837.9 mg/L total polyphenols and 651.3 mg/L RA. Secondary metabolism was further enhanced by elicitation with 100 μm methyl jasmonate applied under optimized bioreactor conditions. In transformed shoot cultures, elicitation increased RA accumulation by 63%, resulting in final productivity of 1164 mg/L RA, and 1250 mg/L total polyphenols. In hairy root cultures, RA accumulation increased by 44%, leading to final productivity of 795 mg/L RA and 933 mg/L total polyphenols. Our findings indicate that the balance between biomass growth and secondary metabolism in S. bulleyana cultures is determined by bioreactor configuration. The nutrient sprinkle bioreactor represents a highly effective platform for phenolic acid production in hairy root cultures, whereas temporary immersion systems can be successfully applied for transformed shoot cultivation. The combination of tailored bioreactor strategies with methyl jasmonate elicitation provides a promising approach for scalable production of high-value phenolic compounds in plant in vitro culture systems. Full article

Exploring plant nutrient allocation and stoichiometry is critical to understanding the adaptive strategies of endangered trees in heterogeneous habitats. This study determined the concentrations of carbon (C), nitrogen (N), phosphorus (P), and potassium (K) in seven organs (leaves, current-year twigs, perennial branches, phloem, xylem, transport roots, and absorptive roots) of Parrotia subaequalis from eight wild populations in the Dabie Mountains and then analyzed the stoichiometric characteristics, chemical plasticity, and allometric relationships of these elements among organs. The concentrations of C, N, P, and K ranged from 416.31–513.61, 4.74–12.99, 0.74–12.89, and 2.62–10.34 mg g⁻¹, respectively. Belowground organs had significantly higher C:P, N:P, and N:K ratios than aboveground ones (by 72.83%–740.30%). Perennial organs (xylem, phloem, perennial branches) showed higher C concentrations and C:N, C:P, C:K, and P:K ratios but lower N, P, and K concentrations than current-year ones (leaves, current-year twigs). Xylem, phloem, and perennial branches exhibited the lowest coefficient of variation and plasticity index. N, P, and K exhibited isometric scaling (α = 0.96–1.04) between absorptive and transport roots. Leaf N and P were positively correlated with K (R² ≥ 0.53). Organ age is a critical determinant influencing the variation in stoichiometric characteristics of the organs. Overall, P. subaequalis adapts to nitrogen-limited wild habitats by adjusting N, P, and K nutrient up-take rates and allocation ratios across current-year organs. Full article