Search Results (245)

Understanding the effect of carbon dioxide (CO₂) modified atmosphere packaging (MAP) on postharvest quality and its molecular mechanism in peanuts will be helpful for the application and optimization of CO₂-MAP. The appearance quality, lipid oxidation indices (acid value, carbonyl value, and malondialdehyde content), DPPH free radical scavenging rate, and the activity of superoxide dismutase (SOD) and lipoxygenase (LOX) of fresh edible peanuts packaged with CO₂ or air (CK, control group) were determined at 7 d intervals for 35 d. Transcriptome sequencing (RNA-seq) of peanuts was performed to identify differentially expressed genes (DEGs) and enriched functional pathways. CO₂-MAP could maintain the appearance quality of peanut pods and kernels. Compared with the control, CO₂-MAP maintained a lower acid value (14.3% lower), carbonyl value (10.7% lower), and malondialdehyde content (22.5% lower), suppressed LOX activity (23.4% lower), as well as retained higher DPPH radical scavenging activity (31.1% higher) and SOD activity (25.0% higher) at 35 d. Transcriptomics identified 3575 downregulated and 2166 upregulated DEGs between the CO₂-MAP and CK. These DEGs were significantly enriched in pathways related to energy metabolism, carbon metabolism, lipid metabolism, signal transduction, and antioxidant functions. Collectively, CO₂-MAP effectively delayed quality deterioration of peanuts by suppressing lipid oxidation, enhancing antioxidant capacity, reprogramming energy metabolism, and attenuating senescence-associated signaling pathways. Full article

To explore the effects of legume intercropping on soil nitrogen (N) and phosphorus (P) cycling processes in mulberry plantations during the winter fallow period, three treatments were set up: control (no intercropping, CK), single-legume intercropping (T1: Medicago polymorpha), and mixed-legume intercropping (T2: Medicago polymorpha + Astragalus sinicus). The variations in soil available nutrients, enzyme activities, microbial community structure, and functional gene abundances were investigated, with a focus on the influence of spatial heterogeneity (middle of inter-row as position A, and mulberry-adjacent as position B). Compared with CK, both T1 and T2 significantly altered soil microbial community composition and enhanced β-diversity (R² = 0.747, p < 0.001), and these effects were more pronounced at position A. For soil N cycling, T1 and T2 reduced available N content especially at position B; however, T2 significantly increased urease activity, while T1 decreased urease activity at position A. Both treatments elevated the abundances of N-cycling functional genes (e.g., glnA, ureC, nifD) and symbiotic nitrogen-fixing rhizobia, with T1 increasing Bradyrhizobium and T2 increasing Sinorhizobium. For soil P cycling, T1 and T2 enhanced phosphatase activity to promote organic P conversion; T1 strengthened the entire P metabolic chain by upregulating multiple P-related functional genes, while T2 specifically increased the abundance of the organic P transport gene ugpb. Structural equation modeling showed that soil microbial Shannon diversity promoted the relative abundances of N-cycling and P-cycling functional genes, and cascading pathways among nutrient-cycling genes and enzyme activities governed soil available N and P. The distinct effects of T1 and T2 highlight the importance of optimizing intercropping patterns, and spatial heterogeneity should be considered in agronomic effect evaluation. Leguminous green manure intercropping should be encouraged in mulberry plantations to boost soil nutrient-cycling processes driven by microorganisms. 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

Vairimorpha ceranae, an obligate intracellular parasitic fungus, infects the midgut of worker Apis cerana cerana, disrupts nutritional metabolism and immune homeostasis of hosts, and poses severe threats to honeybee health and the sustainable development of apiculture. To date, the expression dynamics of circular RNAs (circRNAs) during pathogen infection and their regulatory functions as competing endogenous RNAs (ceRNAs) remain poorly characterized. In this study, circRNA sequencing was performed on purified V. ceranae spores (VcCK), as well as the midguts of A. cerana cerana worker bees at 7 days post-infection (VcT1) and 10 days post-infection (VcT2). A total of 8,986,470 and 315 circRNAs were identified from the three groups, with their lengths predominantly ranging from 200 to 600 nt. Differential expression analysis screened 575 and 594 differentially expressed circRNAs (DEcircRNAs) from the VcCK vs. VcT1 and VcCK vs. VcT2 comparison groups, respectively. The host genes generating these DEcircRNAs were annotated to 316 and 310 GO terms, alongside 167 KEGG pathways. CeRNA network analysis revealed that DEcircRNAs including novel_circ_006653 target multiple miRNAs, and their downstream target mRNAs are significantly enriched in energy metabolism pathways such as carbon metabolism and glycolysis/gluconeogenesis. RT-qPCR validation exhibited high consistency with transcriptome sequencing data. Further analyses demonstrated that V. ceranae infection drastically remodels the circRNA expression landscape: the total number of circRNAs was sharply reduced, and the dominant circRNA subtype shifted from antisense circRNAs to single-exon circRNAs. Several DEcircRNAs (novel_circ_006653, novel_circ_004839, novel_circ_005596, etc.) may participate in pathogen infection progression via the ceRNA regulatory axis by modulating host energy metabolism, immune responses and cellular biological processes. This study provides novel insights into the molecular interaction mechanisms between microsporidian parasites and their honeybee hosts, and identifies potential molecular targets for the prevention and control of microsporidiosis. Full article

Saline–alkali stress is a widespread abiotic stress that severely impairs crop growth and yield formation. Iron Chlorin e6 (ICe6), a novel plant growth regulator, is essentially a chlorophyll derivative, and possesses potential application value in regulating plant chlorophyll metabolism and improving plant stress resistance. In this study, the saline–alkali-sensitive soybean cultivar Henong 95 and saline–alkali-tolerant soybean cultivar Hefeng 50 were used as experimental materials, and foliar spraying with 120 nmol/L ICe6 was conducted at the R1 stage. The results indicated that relative to CK, SA treatment markedly inhibited soybean growth, accompanied by reduced antioxidant capacity, excessive reactive oxygen species (ROS) accumulation and significantly lowered photosynthetic pigment content. Carbohydrate accumulation was substantially suppressed, which ultimately resulted in yield reduction (HN95: −12.31%; HF50: −11.08%). ICe6 treatment mitigated saline–alkali-induced growth inhibition in soybean plants, as reflected by markedly restored antioxidant indices, sharply decreased malondialdehyde (MDA), H₂O₂, and O₂⁻ levels, and notably increased leaf area (HN95: +49.72%; HF50: +19.82%) and chlorophyll content (HN95: +36.06%; HF50: +90.75%). Combined transcriptomic and metabolomic profiling showed that, relative to the SA control, ICe6 treatment led to the identification of 2896 DEGs in HN95 and 3530 DEGs in HF50, with significant enrichment in photosynthesis- and chlorophyll metabolism-related pathways, e.g., GO:0009765 (photosynthesis, light harvesting). Differential metabolites were chiefly enriched in isoflavonoid biosynthesis—a source of antioxidants—and amino acid biosynthesis, which governs chlorophyll precursor synthesis. These findings suggest that ICe6 may enhance chlorophyll content by modulating the expression of genes involved in chlorophyll metabolism, contributing to light capture and chlorophyll biosynthesis, facilitating carbohydrate accumulation and ultimately contributing to increased yield under saline–alkali stress (HN95: +5.74%; HF50: +5.83%). Full article

Variegated sweetpotato leaves are of interest for ornamental and functional-food applications, yet the molecular and metabolic basis of their coloration remains poorly understood. A sweetpotato accession with variegated leaves was found incidentally in the field, with rare and vivid Pink-purple coloration in the apical leaves. To investigate the mechanism underlying this interesting phenotype, this material was maintained in the laboratory, and variegated and normal green leaves from this plant were analysed by transcriptome profiling, miRNA sequencing and metabolome analysis. By integrating differential mRNA expression analysis, target-gene prediction, miRNA sequencing and metabolite identification, we screened candidate miRNA-mRNA modules associated with this leaf-colour formation. Using FDR < 0.05 and |log₂FC| ≥ 1 as thresholds, 49 differentially expressed miRNAs and 692 regulatory relationships involving differentially expressed target mRNAs associated with these miRNAs were identified. Functional annotation indicated that the iba_638_x1- G10133|TU16655 and iba_730_x1- G3592|TU5891 modules were associated with anthocyanin/flavonoid biosynthesis and vacuolar transport, respectively. Metabolome analysis showed that the total relative abundance of flavonoids in Pink leaves was 2.98-fold higher than that in CK, and 28 flavonoids accumulated to more than 2-fold higher levels in Pink than in CK. The differentially accumulated metabolites mainly included anthocyanin glycosides, such as petunidin-3-O-glucoside, delphinidin-3-O-glucoside and cyanidin-3,5-O-diglucoside, and flavonol glycosides, such as quercetin-3-O-sophoroside, isorhamnetin-3-O-glucoside and kaempferol-3-O-sophoroside-7-O-glucoside. These results indicate that the variegated phenotype of Pink leaves is mainly associated with differential accumulation of anthocyanin glycosides and flavonol glycosides. Full article

This study integrated an in vivo feeding trial (0.00–1.00% choline chloride) with in vitro primary hepatocyte experiments to elucidate the molecular mechanisms by which choline chloride alleviates hepatic lipid deposition in bighead carp. The results showed that dietary supplementation with 0.80–1.00% choline chloride significantly reduced hepatic triglyceride (TG) content and lipid droplet accumulation. At the molecular level, choline markedly downregulated lipogenic genes (g6pd, accα, fas) while upregulating genes involved in lipolysis (cpt1α, acox1) and lipid transport (apob-100, mttp). Non-targeted lipidomics revealed that choline maintains lipid homeostasis primarily via the glycerophospholipid metabolism pathway, significantly increasing levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS). Furthermore, choline intervention enhanced the expression of its own metabolism-related genes (slc44a2, chdh, ck, chpt1), accelerating choline transport and phosphorylation. Overall, based on the results of this experiment, 0.80% is the recommended supplemental level of choline chloride in diets, which can effectively alleviate lipid deposition in bighead carp. The mechanism involves inhibiting lipogenesis and promoting lipid decomposition and transport through glycerophospholipid pathways, while simultaneously enhancing PC synthesis to accelerate hepatic lipid export. These findings provide a theoretical basis for precise feed formulation in bighead carp. Full article

Background: Imidacloprid, a widely used neonicotinoid insecticide, is routinely applied to control pests in Astragalus membranaceus var. mongholicus, a crucial medicinal herb producing Astragali Radix. However, the early short-term transcriptional and metabolic responses of its seedlings under imidacloprid gradient stress remain poorly characterized. Methods: In this study, 80-day seedlings were subjected to three foliar spray treatments: blank control (CK), the recommended imidacloprid concentration (2000-fold dilution, 475 mg·L⁻¹), and an excessively high concentration (500-fold dilution, 1900 mg·L⁻¹). Leaf samples were harvested 24 h post-treatment for untargeted ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS) metabolomics (6 biological replicates) and RNA-seq transcriptome sequencing (3 biological replicates). Results: The low- and high-dose treatments induced 1076 and 860 differential metabolites and 6818 and 7283 differentially expressed genes, respectively. Flavonoids, saponins, terpenoids, amino acid metabolites, and energy-related pathways were prominently affected. KEGG enrichment indicated activation of flavone/flavonol biosynthesis, phenylpropanoid metabolism, amino acid metabolism, MAPK signaling, cutin/suberin/wax biosynthesis, and ABC transporter pathways, whereas high-dose exposure was associated with stronger changes in genes related to DNA replication and cell wall remodeling. Integrated network analysis highlighted CHS, PAL, MYC2, KCS, and ABCG40 as candidate regulators linking stress signaling, secondary metabolism, and metabolite transport. Conclusions: Seedlings of A. membranaceus var. mongholicus exhibit dose-dependent acute responses to imidacloprid. Moderate pesticide exposure primarily activates defensive secondary metabolism, whereas excessive dosage triggers genome-wide transcriptional reprogramming. This work identifies key metabolic pathways and hub genes, offering candidate molecular markers for investigating pesticide stress adaptation in medicinal Astragalus and guiding standardized pesticide application in cultivation. Full article

Targeted phototherapy using 308-nm excimer light (EL-308) is widely employed to treat localized skin diseases, such as psoriasis and vitiligo. Although its immunomodulatory effects are well established, tissue-level epidermal responses to EL-308 in human skin explants have not been fully characterized in a controlled ex vivo setting. Therefore, the present study examined dose- and time-dependent changes in keratinocyte proliferation, apoptosis, and differentiation markers in a human organ-cultured skin model without systemic immune inputs (i.e., without circulation-dependent immune-cell recruitment). Human organ-cultured skin samples were irradiated with EL-308 at 300, 400, or 600 mJ/cm² and analyzed on days 2, 5, and 7 using immunohistochemical markers, including Ki-67, TUNEL, CK10, CK16, involucrin, and integrin β1. RNA sequencing was performed 24 h after irradiation with 600 mJ/cm², followed by KEGG and GO enrichment analyses. EL-308 exposure was associated with dose- and time-dependent changes in Ki-67 and TUNEL labeling and with altered expression of differentiation-related markers (integrin β1, CK16, CK10, and involucrin). Transcriptomic analyses revealed enrichment of metabolic and epidermis-related gene sets, including keratinization and epidermal development terms, consistent with a tissue-level response to UVB exposure. These findings provide descriptive data on epidermal marker dynamics and associated transcriptional programs after EL-308 irradiation in human organ-cultured skin and may inform future studies designed to evaluate early damage markers and functional outcomes. Full article

Background/Objectives: Both NPs and Cd alone exert adverse effects on plant growth by disrupting physiological processes and gene expression. However, the mechanisms underlying their combined effects on plant genetic responses remain incompletely understood. Methods: The rice seedlings were used as the experimental material, with the following six treatments established: CK (Control, no NPs and Cd), 10 and 100 mg·L⁻¹ NPs, and 0.5 mg·L⁻¹ Cd alone and combination. Seedlings at the three-leaf stage were treated in hydroponic culture for 7 days, after which root-development parameters, root viability, MDA and soluble sugar contents, and SOD and POD activities were measured, along with transcriptomic analysis. Results: The results show that root length, number of root tips, and root surface area were highest in CK compared with all NPs and Cd treatments, particularly. Significant differences were observed between the CK and both the high-concentration NPs and all Cd treatments groups (p < 0.05). Root growth progressively declined with increasing NP concentrations; the combination of 100 mg·L⁻¹ NPs and 0.5 mg·L⁻¹ Cd exhibited synergistic toxicity, which decreased root length, number of root tips, and root surface area by 14%, 22%, and 4% compared with 0.5 Cd, whereas 10 mg·L⁻¹ NPs significantly alleviated Cd-induced root damage for the three root parameters above in the following order: 0.5 Cd < 0.5 Cd-10 NPs < 10 NPs. In terms of physiological changes, 10 mg·L⁻¹ NPs reduced MDA levels and enhanced SOD and POD activities in roots exposed to Cd; in contrast, 100 mg·L⁻¹ NPs exacerbated Cd-induced membrane peroxidation and decreased SOD and POD activities. In the high-concentration NPs and all Cd-treated groups, all aforementioned indicators exhibited significant differences compared with the CK (p < 0.05). Transcriptomic and WGCNA analyses revealed that the expression levels of OsGRP162 (regulating resistance) and OsCYP2 (inhibiting lateral root formation under overexpression) were significantly higher in 0.5 Cd-100 NPs compared with the other five treatments, while OsTubA2 (positively regulating root length) exhibited a different pattern. Differentially expressed genes (DEGs) in experimental groups of 10 NPS_vs_0.5 Cd-10 NPS and 100 NPS_vs_0.5 Cd-100 NPS were predominantly enriched in glutathione metabolism and the MAPK signaling pathway, respectively. The key genes OsMT4C, OsMT4B and OsYSL2 (associated with transmembrane signal transduction), and OsABCB5 and OsCUL1-3 (involved in negative regulation of root elongation) exhibited reduced expression levels in 0.5 Cd-10 NPs, whereas OsYDA2 and OsAGO1c (related to antioxidant defense) showed upregulated expression. Conversely, the opposite gene expression patterns were observed in 0.5 Cd-100 NPs. Conclusions: These findings demonstrate that both NPs and Cd adversely affect rice seedlings; however, low concentrations of NPs mitigate Cd toxicity, while high concentrations exacerbate it. Therefore, to prevent elevated NP concentrations in plant growth environments, plastic usage and processing should be standardized. Full article

The purpose of this study was to offer a theoretical foundation for the use of curcumin in poultry systems for anti-stress responses. Fourteen-day-old SPF Leghorn embryonic eggs were isolated and digested to produce primary cultured cardiomyocytes for this investigation. The primary cultured cardiomyocytes were divided into three groups: the CK group, serving as the control check; the HS group, which underwent a heat stress challenge; and the HS_Cur group, which was pre-treated with curcumin prior to experiencing heat stress. Twenty hours prior to the heat stress phase, the HS_Cur group received 15 μmol/L of curcumin. The culture medium’s cells and supernatant were extracted. Curcumin has been shown to protect cells against heat stress by drastically inhibiting the release of CK-MB and LDH, reducing the generation of MDA, and improving the potential of the mitochondrial membrane. Heat stress may alter cell proliferation, the base repair process, and cause proteotoxic stress, according to pathway enrichment analysis. Several iron metabolism-related pathways were both shown in CK vs. HS and HS vs. HS_Cur comparisons. Curcumin can promote heme synthesis and improve iron storage and antioxidant capacity by suppressing the expression of FTL, MAP1LC3C, and FXN and increasing the expression of SLC7A11, FTH1, FECH, SQSTM1, and NQO1, according to our subsequent analysis of iron metabolism-related DEGs. Curcumin may protect cells from the toxicity of LIP by inhibiting the expression of ferritinophagy-related genes and increasing the expression of heme production, iron storage, and antioxidant-related genes. Full article

Magnesium (Mg) deficiency is common in acidic orchard soils and can limit fruit crop growth and quality. This study evaluated whether foliar-applied magnesium oxide nanoparticles (MgO NPs) could improve Mg nutrition and fruit quality in ‘Ninghaibai’ loquat grown under Mg-deficient acidic soil conditions. Pot and field experiments were conducted using water as the control and MgSO₄-50eq as an equimolar Mg comparator. MgO NPs showed a concentration-dependent effect, and 200 mg/L produced the best overall performance among the tested concentrations. At this concentration, total biomass increased by 47.27%, compared with CK, accompanied by enhanced chlorophyll accumulation, antioxidant enzyme activities, and Mg uptake. In fruit, 200 mg/L MgO NPs increased soluble solids content by 45.67% and reduced titratable acidity by 53.26%, while also improving fruit size and sugar–acid balance. Leaf transcriptome analysis suggested that MgO NPs altered the expression of genes involved in metabolism, stress response, and secondary metabolite biosynthesis. At the 50 mg/L level, MgO NPs produced stronger responses than the equimolar MgSO₄ treatment in Mg uptake, nutrient acquisition, and several fruit-quality traits. However, excessive application at 500 mg/L weakened growth and quality improvement. Overall, foliar application of 200 mg/L MgO NPs may represent a promising strategy for improving loquat growth and fruit quality under the tested Mg-deficient conditions. Full article

Soil moisture plays a crucial regulatory role in determining the size and quality of citrus fruits. This study analyzed the fruit size and quality of citrus under different soil moisture conditions, including severe drought (SD), moderate drought (MD), and control (CK). Under drought stress, the fruit weight, longitudinal diameter, and transverse diameter of citrus fruits were significantly lower than those of the control. The content of soluble solids and titratable acid in fruits under drought stress was significantly higher than that of the control. Transcriptome sequencing revealed that compared with CK, there were 1186 differentially expressed genes in MD, including 414 up-regulated genes and 772 down-regulated genes; and 2315 differentially expressed genes in SD, including 1143 up-regulated genes and 1172 down-regulated genes. The differentially expressed genes were significantly enriched in cellular processes, metabolic processes, and plant hormone signal transduction. The down-regulated expression of auxin and gibberellin biosynthesis genes (YUC10, GA20_OX1, GA2_OX1, and GA20_OX2) and signal transduction-related genes (AUX/IAA13, SAUR32, GH3.1, and ARRs), and the up-regulated expression of cytokinin decomposition gene (CKX5) may be associated with reduced fruit size under drought conditions. The up-regulated expression of citric acid synthesis genes (PEPC2 and PEPCK1) and vacuolar transporters (PH1, PH4, PH8, and VHA-c3) may be associated with pronounced accumulation of citric acid in citrus under drought stress. In conclusion, water control regulated fruit size and acidity by modulating phytohormone metabolism and signaling, along with the synthesis and transport of citric acid. Full article

Global warming exacerbates high-temperature stress, disturbing the growth, metabolic homeostasis and quality formation of tea plants (Camellia sinensis L.). Trehalose, a multifunctional osmolyte, can enhance abiotic stress tolerance, but its systematic metabolic mechanism against heat damage in tea remains unclear. Here, we applied integrated gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS) non-targeted metabolomics to compare control (CK), heat-stressed (T), and trehalose-treated heat-stressed (TT) tea leaves. We identified 163 differential volatile metabolites in GC-MS and 1619 differential non-volatile metabolites in LC-MS. Metabolite classification showed that organic oxygen compounds dominated differential volatile metabolites, while lipids and lipid-like molecules dominated differential non-volatile metabolites. The Kyoto Encyclopedia of Genes and Genomes enrichment showed that alanine, aspartate and glutamate metabolism, arginine biosynthesis, aminoacyl-tRNA biosynthesis, and flavone and flavonol biosynthesis were core shared pathways. Quantitatively, exogenous trehalose under heat stress significantly increased carbohydrate accumulation, restored lipid homeostasis, and elevated alanine, arginine, and related intermediates, thereby maintaining carbon–nitrogen balance. Trehalose also remodeled the amino acid substrate pool for aminoacyl-tRNA biosynthesis. In flavonoid metabolism, trehalose enhanced high-antioxidant flavonoid aglycones while reducing most glycosides and inhibiting excessive hydroxylation of flavonols. Although total flavonoid content decreased in TT relative to T, this reflected alleviated oxidative damage and reduced dependence on flavonoid-based defense. Combined with total amino acid and flavonoid quantifications, we conclude that exogenous trehalose enhances tea plant thermotolerance by coordinately regulating primary amino acid metabolism and secondary flavonoid metabolism. These findings provide a theoretical basis for using trehalose in heat-resistance cultivation and quality improvement of tea plants. Full article

The rhizosphere microbiome and phytohormone signaling are critical determinants of plant growth and stress resilience. This study evaluated the combined effects of Streptomyces sp. HU2014 and coronatine (COR) on maize (Zea mays L.) seedlings. Four treatments were established: control (CK), COR seed soaking (Cor), HU2014 soil inoculation (S), and combined S + Cor (SCor). Growth parameters, chlorophyll content, and antioxidant/oxidative stress markers were measured, and root and leaf transcriptomes, together with root metabolomes, were compared between SCor and CK, followed by qRT-PCR validation. Compared with CK, SCor treatment significantly increased stem diameter (~60%), plant height (~20%), and relative chlorophyll content (SPAD, ~50%). Soluble sugar levels were elevated by over 40% in both leaves and roots, accompanied by tissue-specific modulation of antioxidant enzymes. Transcriptomic analysis of SCor vs. CK revealed 2459 differentially expressed genes (DEGs) in leaves and 3444 DEGs in roots; leaves exhibited upregulation of photosynthetic pigment metabolism (porphyrin and carotenoid pathways) and volatile defense compounds (alkaloids and monoterpenoids), whereas roots showed enrichment in phenylpropanoid/flavonoid biosynthesis, benzoxazinoid synthesis, and starch/sucrose metabolism. Metabolomics of SCor vs. CK identified 526 differentially accumulated metabolites (DAMs) in roots, with significant enrichment in aminoacyl-tRNA biosynthesis, phenylalanine metabolism, and linoleic acid metabolism. Integrative multi-omics analysis further revealed that the JA precursor 13-epi-12-oxo-phytodienoic acid co-clustered with stress-responsive transcription factors (e.g., DREB1C), while tricarboxylic acid (TCA) intermediates and phenylpropanoid metabolites were linked to energy and lignin biosynthesis genes. qRT-PCR confirmed the expression trends of 14 out of 15 tested genes. Collectively, combined HU2014 and COR application triggers tissue-specific transcriptional and metabolic reprogramming in maize, coupling JA-mediated stress signaling with enhanced carbon metabolism and secondary defense compound synthesis to promote rhizosphere adaptation and seedling vigor. Full article