Search Results (191)

In order to achieve the efficient utilization of agricultural by-products and overcome the bottleneck of animal feed shortages in dry seasons, this study utilized corn stover (CS; Zea mays L.) as a material to systematically investigate the dynamic changes in the fermentation quality, bacterial community structure, and pathogenic risk of silage under different fermentation times (0, 3, 7, 15, and 30 days). CS has high nutritive value, including crude protein and sugar, and can serve as a carbon source and a nitrogen source for silage fermentation. After ensiling, CS silage (CSTS) exhibited excellent fermentation quality, characterized by relatively high lactic acid content, low pH, and ammonia nitrogen content within an acceptable range. In addition, neither propionic acid nor butyric acid was detected in any of the silages. CS exhibited high α-diversity, with Serratia marcescens being the dominant bacterial species. After ensiling, the α-diversity significantly (p < 0.05) decreased, and Lactiplantibacillus plantarum was the dominant species during the fermentation process. With the extension of fermentation days, the relative abundance of Lactiplantibacillus plantarum significantly (p < 0.05) increased, reaching a peak and stabilizing between 15 and 30 days. Ultimately, lactic acid bacteria dominated and constructed a microbial symbiotic network system. In the bacterial community of CSTS, the abundance of “potential pathogens” was significantly (p < 0.01) lower than that of CS. These results provide data support for establishing a microbial regulation theory for silage fermentation, thereby improving the basic research system for the biological conversion of agricultural by-products and alleviating feed shortages in dry seasons. Full article

Quercus acutissima seeds exhibit high desiccation sensitivity, posing significant challenges for long-term preservation. This study investigates the physiological and metabolic responses of soluble osmoprotectants—particularly soluble proteins and proline—during the desiccation process. Seeds were sampled at three critical moisture content levels: 38.8%, 26.8%, and 14.8%, corresponding to approximately 99%, 52%, and 0% germination, respectively. We measured germination ability, soluble protein content, and proline accumulation, and we performed untargeted metabolomic profiling using LC-MS. Soluble protein levels increased early but declined later during desiccation, while proline levels continuously increased for sustained osmotic adjustment. Metabolomics analysis identified a total of 2802 metabolites, with phenylpropanoids and polyketides (31.12%) and lipids and lipid-like molecules (29.05%) being the most abundant. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that differentially expressed metabolites were mainly enriched in key pathways such as amino acid metabolism, energy metabolism, and nitrogen metabolism. Notably, most amino acids decreased in content, except for proline, which showed an increasing trend. Tricarboxylic acid cycle intermediates, especially citric acid and isocitric acid, showed significantly decreased levels, indicating energy metabolism imbalance due to uncoordinated consumption without effective replenishment. The reductions in key amino acids such as glutamic acid and aspartic acid further reflected metabolic network disruption. In summary, Q. acutissima seeds fail to establish an effective desiccation tolerance mechanism. The loss of soluble protein-based protection, limited capacity for proline-mediated osmotic regulation, and widespread metabolic disruption collectively lead to irreversible cellular damage. These findings highlight the inherent metabolic vulnerabilities of recalcitrant seeds and suggest potential preservation strategies, such as supplementing critical metabolites (e.g., TCA intermediates) during storage to delay metabolic collapse and mitigate desiccation-induced damage. Full article

Background: Huang Qin Decoction (HQD) is a well-established Traditional Chinese Medicine (TCM) formulation recognized for its application in the treatment of colorectal cancer (CRC). However, the precise therapeutic mechanisms remain inadequately defined. Methods: This study integrates metabolomics from a mouse model and network pharmacology to screen potential targets and bio-active ingredients of HQD. The pharmacological activity of HQD for CRC was evidenced via single-cell RNA sequencing (scRNA-seq), molecular docking, and molecular dynamics simulations. Atomic force microscopy (AFM) assays and cellular experimental validation were used to confirm the relative mechanisms. Results: The metabolite profile undergoes significant alterations, with metabolic reprogramming evident during the malignant progression of CRC liver metastasis. Network pharmacology analysis identified that HQD regulates several metabolic pathways, including arginine biosynthesis, alanine, aspartate, and glutamate metabolism, nitrogen metabolism, phenylalanine metabolism, and linoleic acid metabolism, by targeting key proteins such as aspartate aminotransferase (GOT1), cytochrome P450 1A2 (CYP1A2), and carbonic anhydrase 2 (CA2). ScRNA-seq analysis indicated that HQD may enhance the functionality of cytotoxic T cells, thereby reversing the immunosuppressive microenvironment. Virtual verification revealed a strong binding affinity between the identified hub targets and active constituents of HQD, a finding subsequently corroborated by AFM assays. Cellular experiments confirmed that naringenin treatment inhibits the proliferation, migration, and invasion of CRC cells by downregulating GOT1 expression and disrupting glutamine metabolism. Conclusions: Computational prediction and in vitro validation reveal the active ingredients, potential targets, and molecular mechanisms of HQD against CRC liver metastasis, thereby providing a scientific foundation for the application of TCM in CRC treatment. Full article

Petroleum-contaminated soil is an increasingly severe environmental issue. The integration of phytoremediation and microbial remediation can effectively mitigate their individual limitations and enhance remediation efficiency. In this study, four newly isolated bacterial strains (including Cytobacillus and Rhodococcus) that exhibited preferential degradation of distinct petroleum components were combined with the rhamnolipid-producing strain Pseudomonas aeruginosa SL-1. The immobilization of this petroleum-degrading microbial consortium was performed by biochar adsorption and sodium alginate embedding, subsequently optimized using response surface methodology (0.75 g·L⁻¹ of biochar, 40 g·L⁻¹ of sodium alginate, and 40 g·L⁻¹ of calcium chloride). The results showed that the highest petroleum degradation rate (97.1%) of immobilized bacterial consortium was achieved at 72 h at a petroleum concentration of 5.0 g·L⁻¹. When combined with Sudan grass for soil bioremediation, the degradation rate reached 72.8% after 120 d for soil containing 5.0 g·kg⁻¹ of petroleum, higher than the results for the treatments with only immobilized bacterial consortium (53.0%) or Sudan grass (49.2%). Furthermore, significant improvements were observed for soil pH; nitrogen, phosphorus, and potassium contents; and urease, dehydrogenase, and catalase activities. Composite treatment also significantly increased the diversity and richness of the soil bacterial community and regulated its structure, function, and network composition. This study offers theoretical insights and potential practical applications for the enhanced bioremediation of petroleum-contaminated soils. Full article

Potassium (K), a critical macronutrient for the growth and development of Korla fragrant pear (Pyrus sinkiangensis Yu), plays a pivotal regulatory role in sugar-acid metabolism. Furthermore, K exhibits a highly specific response in near-infrared (NIR) spectroscopy compared to elements such as nitrogen (N) and phosphorus (P). Given its fundamental impact on fruit quality parameters, the development of rapid and non-destructive techniques for K determination is of significant importance for precision fertilization management. By measuring leaf potassium content at the fruit setting, expansion, and maturity stages (decreasing from 1.60% at fruit setting to 1.14% at maturity), this study reveals its dynamic change pattern and establishes a high-precision prediction model by combining near-infrared spectroscopy (NIRS) with machine learning algorithms. “Near-infrared spectroscopy coupled with machine learning can enable accurate, non-destructive monitoring of potassium dynamics in Korla pear leaves, with prediction accuracy (R²) exceeding 0.86 under field conditions.” We systematically collected a total of 9000 leaf samples from Korla fragrant pear orchards and acquired spectral data using a benchtop near-infrared spectrometer. After preprocessing and feature extraction, we determined the optimal modeling method for prediction accuracy through comparative analysis of multiple models. Multiplicative scatter correction (MSC) and first derivative (FD) are synergistically employed for preprocessing to eliminate scattering interference and enhance the resolution of characteristic peaks. Competitive adaptive reweighted sampling (CARS) is then utilized to screen five potassium-sensitive bands, specifically in the regions of 4003.5–4034.35 nm, 4458.62–4562.75 nm, and 5145.15–5249.29 nm, among others, which are associated with O-H stretching vibration and changes in water status. A comparison between random forest (RF) and BP neural network indicates that the MSC + FD–CARS–BP model exhibits the optimal performance, achieving coefficients of determination (R²) of 0.96% and 0.86% for the training and validation sets, respectively, root mean square errors (RMSE) of 0.098% and 0.103%, a residual predictive deviation (RPD) greater than 3, and a ratio of performance to interquartile range (RPIQ) of 4.22. Parameter optimization revealed that the BPNN model achieved optimal stability with 10 neurons in the hidden layer. The model facilitates rapid and non-destructive detection of leaf potassium content throughout the entire growth period of Korla fragrant pears, supporting precision fertilization in orchards. Moreover, it elucidates the physiological mechanism by which potassium influences spectral response through the regulation of water metabolism. Full article

Background: Obesity-associated metabolic disorders represent a critical global health challenge, which necessitates innovative strategies targeting lipid metabolism. Peanut skin procyanidins (PSPs), abundant bioactive compounds derived from agricultural by-products, show potential in lipid regulation, but molecular mechanisms remain unclear. Methods: This study integrated hepatic metabolomics, network pharmacology, and gut microbiota analysis to systematically decipher the mechanisms for PSP to ameliorate high-fat diet (HFD)-induced lipid metabolism disorders. Results: PSP intervention significantly attenuated HFD-induced increases in LDL-C, TG, and TC levels and effectively mitigated hepatic lipid accumulation. Metabolomics revealed that PSP reshaped hepatic lipid dynamics by modulating glycerophospholipid, linoleic acid, arachidonic acid, tryptophan, and nitrogen metabolism. Subsequent network pharmacology identified PLA2G10, PLA2G5, PLA2G2A, and CYP1B1 as the core targets, and PSP could markedly suppress their HFD-induced overexpression. Furthermore, PSP selectively reshaped the gut microbiota, enriching beneficial genera such as Akkermansia and Bacteroides while reducing the abundance of harmful bacteria within Firmicutes. PICRUSt-based functional prediction indicated that PSP alters gut microbial glutamine synthetase activity. Conclusions: Mechanistically, PSP regulates lipid metabolism by downregulating PLA2G10, PLA2G5, PLA2G2A, and CYP1B1 expression, remodeling gut microbiota structure, and increasing hepatic glutamine level. These findings provide novel insights into value-added utilization of agricultural byproducts and development of targeted intervention strategies for metabolic diseases. Full article

Background: Aluminum (Al) toxicity severely limits Medicago sativa (alfalfa) production on acidic soils, resulting in major yield losses worldwide. The highly conserved miRNA156 (miR156) functions by downregulating at least 11 SQUAMOSA promoter-binding protein-like (SPL) transcription factors in alfalfa, including SPL13, but its role in Al stress remains unclear. This study aimed to investigate the miR156/SPL regulatory network’s function in alfalfa under Al stress. Methods: Gene expression analyses, histochemical staining, nutrient profiling, phenotypic assays, transcriptome profiling, and ChIP-seq were conducted on alfalfa plants with altered miR156 and SPL13 expression to assess their roles in the Al stress response. Results: Al stress induced SPL13 expression while repressing miR156 in the roots. Elevated miR156 intensified Al accumulation, lipid peroxidation, and plasma membrane damage, accompanied by reduced leaf nitrogen, magnesium, sulfur, and phosphorus content. Phenotypically, increased SPL13 enhanced the root length and Al tolerance, whereas SPL13 silencing reduced tolerance. Transcriptome profiling of SPL13-silenced plants identified differentially expressed genes involved in the Al response, including aluminum-activated malate transporters and various transcription factors (GRAS, Myb-related, bHLH041, NAC, WRKY53, bZIP, and MADS-box). ChIP-seq revealed that SPL13 directly regulates genes encoding a protein kinase, cytochrome P450, and fasciclin-like arabinogalactan proteins. Conclusions: The MsmiR156/MsSPL13 network plays a crucial regulatory role in alfalfa’s response to Al toxicity. These findings provide novel genetic targets and foundational knowledge to advance molecular breeding for enhanced Al tolerance in alfalfa. Full article

Excessive fertilizer input and low output are currently problems for peach production in China. Sugar alcohols such as sorbitol and mannitol represent promising eco-friendly fertilization strategies to improve fruit quality and optimize nutrient management. Our research explored the effect of sorbitol and mannitol on the rhizosphere environment and peach growth from the rhizosphere micro-ecology perspective. Potted peach seedlings were used as materials. Without adding or adding different sorbitol and mannitol concentration gradients (100, 200, 400) combined with potassium dihydrogen phosphate (KH₂PO₄), the physicochemical properties of rhizosphere soil, leaf nutrition, photosynthetic and growth index were determined, and the rhizosphere bacterial community was analyzed via Illumina Miseq high-throughput sequencing. Both sorbitol and mannitol altered the rhizosphere environment, effectively improved leaf photosynthesis, and promoted peach seedling growth; particularly, M100 had optimal affection. Sorbitol and mannitol altered the bacterial structure and reduced bacterial diversity, which observably correlated with soil organic matter and available potassium. For the rhizosphere bacterial composition, sorbitol and mannitol increased specific bacterial OTUs and induced changes in bacterial composition, among which chemoheterotrophic and nitrogen-transforming bacteria increased with the addition of sorbitol and mannitol. Association network analysis and a structural equation model showed that S100 and M100 mainly enriched Vicinamibacteraceae to regulate peach seedling growth. Overall, low-concentration sorbitol and mannitol showed the best effect in peach seedling growth through regulating the rhizosphere environment. Full article

Modified biochar can effectively improve the quality and environment of coastal saline–alkali soil, but its effects on the growth and development of halophytes and its mechanism are still unclear. This study systematically evaluated the growth-promoting effects and preliminary mechanisms of H₃PO₄-modified biochar (HBC) and H₃PO₄–kaolinite–biochar composite (HBCK) on the economically important halophyte Kosteletzkya virginica. The results demonstrated that the application of HBC/HBCK significantly enhanced plant growth, resulting in increases of over 55% in plant height and greater than 100% in biomass relative to the control. Multidimensional mechanistic analysis revealed the following: (1) accumulation of nitrogen (N), phosphorus (P), and potassium (K) increased by at least 40%, significantly enhancing nutrient uptake; (2) increases in the activities of superoxide dismutase (SOD) and peroxidase (POD) by over 100% and 70%, respectively, markedly boosting antioxidant capacity and effectively alleviating oxidative stress; (3) molecular regulation via the activation of transcription factor networks (HSP, MYB, TCP, AP2/ERF, bZIP, and NLP) and modulation of key genes in ABA, BR, and JA signaling pathways (CYP707A, CYP90, and OPR2), establishing a multi-layered stress adaptation and growth promotion system. Beyond assessing the growth-promoting effects of modified biochars, this study provides novel insights into the regulatory transcription factor networks and phytohormone signaling pathways, offering theoretical foundations for the molecular design of biochars for saline–alkali soil remediation. Full article

The root system is vital for Brassica napus water/nutrient uptake and anchorage, highlighting the importance of identifying root development genes (RDGs). In this study, we identified 218 RDGs in B. napus through homology-based retrieval. Phylogenetic analysis of 22 representative species revealed that the RDGs are widely present in plants ranging from aquatic algae to angiosperms. RDGs in B. napus expanded through whole-genome duplication (WGD) events between Brassica rapa and Brassica oleracea ancestors and smaller duplications specific to B. napus. Promoter analysis identified 115 cis-elements, mainly abiotic stress-related and light-responsive. Transcription factor networks showed regulation by BBR-BPC, MIKC_MADS, AP2, and GRAS families. Transcriptome analysis under multiple stresses revealed that low nitrogen (LN) induced the most pronounced changes, with >50% (109/218) of RDGs differentially expressed in roots. Furthermore, we screened the BnaSHR-6 gene, which is co-localized in both primary roots (PR) and lateral roots (LR), and responds strongly to LN. Phenotypic analysis revealed that the BnaSHR-6 gene regulates the growth and development of both PR and LR under LN conditions, and confers a degree of resistance. These findings advance our understanding of RDGs in B. napus and provide valuable gene resources for subsequent molecular breeding. Full article

This study examines the impact of continuous cropping (short-term: 1–8 years; medium-term: 9–15 years; long-term: 16–30 years) on soil microbial community diversity, co-occurrence networks, and assembly processes in Xinjiang’s cotton region, a globally recognized arid zone. The results are as follows. Soil physicochemical analyses showed that as continuous cropping duration increased, soil organic matter and total nitrogen significantly decreased, whereas available phosphorus and potassium increased, and the soil’s aggregate structure degraded. Microbial community analysis indicated that long-term continuous cropping notably increased the richness of bacterial species (Chao1 index) and altered fungal communities’ diversity and composition, especially increasing the relative abundance of Cladosporium and Alternaria in the long term (GY30). Co-occurrence network analysis revealed higher complexity in bacterial and fungal networks in the short term. As cropping duration increased, bacterial network complexity significantly decreased, while fungal networks partially recovered in the long term, indicating greater fungal adaptability to environmental changes. Assembly process analysis revealed that the assembly of bacterial and fungal communities was jointly regulated by stochastic and deterministic processes, but with increasing cropping duration, deterministic processes weakened while stochastic processes intensified. Soil available phosphorus, potassium, and pH were identified as key factors influencing microbial community succession and assembly. This study highlights the significance of co-occurrence networks and assembly processes for understanding the dynamics of continuous cropping’s impact on soil microbial communities, offering a theoretical foundation for improving agricultural management. Full article

Carbon (C), nitrogen (N), and phosphorus (P) act as pivotal regulators of biogeochemical cycles, steering organic matter decomposition and carbon sequestration in terrestrial ecosystems through the stoichiometric properties of photosynthetic organs. Deciphering their multi-scale spatiotemporal dynamics is central to unraveling plant nutrient strategies and their coupling mechanisms with global element cycling. In the current study, we modeled biogeochemical parameters (C/N/P contents, stoichiometry, and pools) in plant aboveground parts by using the growing mean temperature, total precipitation, total radiation, and maximum normalized difference vegetation index (NDVImax) across nine models (i.e., random forest model, generalized boosting regression model, multiple linear regression model, artificial neural network model, generalized linear regression model, conditional inference tree model, extreme gradient boosting model, support vector machine model, and recursive regression tree) in Xizang grasslands. The results showed that the random forest model had the highest predictive accuracy for nitrogen content, C:P, and N:P ratios under both grazing and fencing conditions (training R² ≥ 0.61, validation R² ≥ 0.95). Additionally, the random forest model had the highest predictive accuracy for C:N ratios under fencing conditions (training R² = 0.84, validation R² = 1.00), as well as for C pool and P content and pool under grazing conditions (training R² ≥ 0.62, validation R² ≥ 0.90). Therefore, the random forest algorithm based on climate data and/or the NDVImax demonstrated superior predictive performance in modeling these biogeochemical parameters. Full article

The monoculture planting in terraced tea plantations has led to severe soil degradation, which poses a significant threat to the growth of tea plants. However, the mechanisms by which intercropping systems improve soil health through the regulation of soil microbial communities at the micro-topographical scale of terraced tea plantations (i.e., terrace surface, inter-row, and terrace wall) remain unclear. This study investigates the effects of intercropping Ophiopogon japonicus in a five-year tea plantation on the soil physicochemical properties, enzyme activities, and microbial community structure and functions across different micro-topographical features of terraced tea plantations in Wuyi Mountain. The results indicate that intercropping significantly improved the soil organic matter, available nutrients, and redox enzyme activities in the inter-row, terrace surface, and terrace wall, with the effects gradually decreasing with increasing distance from the tea plant rhizosphere. In the intercropping group, tea leaf yield increased by 13.17% (fresh weight) and 19.29% (dry weight) compared to monoculture, and the disease indices of new and old leaves decreased by 40.63% and 38.7%, respectively. Intercropping strengthened the modularity of bacterial networks and the role of stochasticity in shaping bacterial communities in different micro-topographic environments, in contrast to the patterns observed in fungal communities. The importance of microbial phyla such as Proteobacteria and Ascomycota in different micro-topographical features was significantly regulated by intercropping. In different micro-topographical zones of the terraced tea plantation, beneficial bacterial genera such as Sinomonas, Arthrobacter, and Ferruginibacter were significantly enriched, whereas potential fungal pathogens like Nigrospora, Microdochium, and Periconia were markedly suppressed. Functional annotations revealed that nitrogen cycling functions were particularly enhanced in inter-row soils, while carbon cycling functions were more prominent on the terrace surface and wall. This study sheds light on the synergistic regulatory mechanisms between micro-topographical heterogeneity and intercropping systems, offering theoretical support for mitigating soil degradation and optimizing management strategies in terraced tea agroecosystems. Full article

Despite substantial research on how environmental factors affect fungal diversity, the mechanisms shaping regional-scale diversity patterns remain poorly understood. This study employed ITS high-throughput sequencing to evaluate soil fungal diversity, community composition, and co-occurrence networks across alpine meadows, desert steppes, and alpine shrublands in the southwestern Tibetan Plateau. We found significantly higher fungal α-diversity in alpine meadows and desert steppes than in alpine shrublands. Random forest and CAP analyses identified the mean annual temperature (MAT) and normalized difference vegetation index (NDVI) as major ecological drivers. Mantel tests revealed that soil physicochemical properties explained more variation than climate, indicating an indirect climatic influence via soil characteristics. Distance–decay relationships suggested that environmental heterogeneity and species interactions drive community isolation. Structural equation modeling confirmed that the MAT and NDVI regulate soil pH and carbon/nitrogen availability, thereby influencing fungal richness. The highly modular fungal co-occurrence network depended on key nodes for connectivity. Vegetation coverage correlated positively with network structure, while soil pH strongly affected network stability. Spatial heterogeneity constrained stability and diversity through resource distribution and niche segregation, whereas stable networks concentrated resources among dominant species. These findings enhance our understanding of fungal assemblage processes at a regional scale, providing a scientific basis for the management of soil fungal resources in plateau ecosystems. Full article

Cold stress critically restricts maize seedling growth in Northeast China, yet the mechanism by which cold priming (CP) enhances cold tolerance through proline–nitrogen metabolic networks remains unclear. This study systematically investigated CP’s synergistic regulation in cold-tolerant (Heyu27) and cold-sensitive (Dunyu213) maize using a two-phase temperature regime (priming induction/stress response) with physiological and multivariate analyses. CP alleviated cold-induced photosynthetic inhibition while maintaining a higher chlorophyll and photosynthetic rate, though biomass responses showed varietal specificity, with Heyu27 minimizing growth loss through optimized carbon–nitrogen allocation. Antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were pre-activated during early stress, effectively scavenging reactive oxygen species (ROS) and reducing malondialdehyde (MDA) accumulation, with Heyu27 showing superior redox homeostasis. CP enhanced proline accumulation via bidirectional enzyme regulation (upregulating ∆¹-pyrroline-5-carboxylate synthase/reductase [P5CS/P5CR], inhibiting proline dehydrogenase [ProDH]) and reprogrammed nitrogen metabolism through glutamate dehydrogenase/isocitrate dehydrogenase (GDH/ICDH)-mediated ammonium conversion to glutamate, alleviating nitrogen dysregulation while supplying proline precursors. Principal component analysis revealed divergent strategies: Heyu27 prioritized proline–antioxidant synergy, whereas Dunyu213 emphasized photosynthetic adjustments. These findings demonstrate that CP establishes “metabolic memory” through optimized proline–nitrogen coordination, synergistically enhancing osmoregulation, reactive oxygen species (ROS) scavenging, and nitrogen utilization. This study elucidates C₄-specific cold adaptation mechanisms, advancing cold-resistant breeding and stress-resilient agronomy. Full article