Search Results (2,173)

Identifying plant-growth-promoting rhizobacteria tolerant to saline–alkali conditions is critical for developing effective microbial agents and multi-strategy approaches to remediate saline–alkali soil. Two salt–alkali-tolerant bacterial strains—phosphorus-solubilizing Bacillus pumilus JL-C and cellulose-decomposing B. halotolerans XW-3—were isolated from saline–alkali soil, with both exhibiting multiple plant-growth-promoting properties, including nitrogen fixation and the generation of indole-3-acetic acid, siderophores, and 1-aminocyclopropane-1-carboxylate deaminase. Alfalfa pot experiments were conducted under four treatments: a control, the strain JL-C treatment, the strain XW-3 treatment, and a co-inoculation treatment (JL-C/XW-3), all mixed with corn straw and applied to the saline–alkali soil. The results demonstrated that the co-inoculation treatment yielded the most significant growth-promoting effects on alfalfa, showing enhanced antioxidant enzyme activities; increased contents of proline, soluble sugar, and protein; reduced malondialdehyde content; lowered pH and electrical conductivity; elevated activities of key enzymes; and increased levels of available nitrogen, phosphorus, potassium, and organic matter content in the soil. The pot experiments were confirmed by field experiments. The results of 16S rRNA high-throughput sequencing revealed changes in the bacterial community composition in the alfalfa rhizosphere, showing shifts in the relative abundance of several bacterial taxa often reported as plant-associated or potentially beneficial. This study establishes a combined remediation strategy for saline–alkali soil utilizing complex microbial agents and corn straw. Full article

Soil salinization is a major threat to agricultural sustainability. Poly-gamma-glutamic acid (γ-PGA), a biopolymer produced by microbial fermentation, has received attention as a biostimulant due to its positive effects on crop performance. However, the function of γ-PGA in crop salt stress tolerance and its effect on the rhizosphere are unclear. This study explores the effects of γ-PGA application on rhizosphere soil nutrients and the soil–physical environment and examines the salt tolerance response of maize seedlings grown in saline–alkali soil under such an application regime. The results show a significant promotion of maize seedling growth and of nutrient accumulation with γ-PGA application under salt stress; plant dry weight, stem diameter, and plant height increased 121%, 39.5%, 18.4%, respectively, and shoot accumulation of nitrogen, phosphorus, potassium, and carbon increased by 1.38, 2.11, 1.50, and 1.36 times, respectively, under an optimal-concentration γ-PGA treatment (5.34 mg kg⁻¹ (12 kg ha⁻¹)) compared with the control. γ-PGA treatment significantly decreased rhizospheric pH and soil electrical conductivity and significantly increased nutrient availability in the rhizosphere, especially available nitrogen (AN) and available potassium (AK). Compared with the control, AN, available phosphorus (AP), and AK increased by 13.9%, 7.70%, and 17.7%, respectively, under an optimal concentration treatment with γ-PGA. γ-PGA application also significantly increased the activities of urease, acid phosphatase, alkaline phosphatase, dehydrogenase, and cellulose in rhizosphere soil by 35.5–39.3%, 35.4–39.3%, 5.59–8.85%, 18.9–19.8%, and 19.2–47.0%, respectively. γ-PGA application significantly decreased Na⁺ concentration and increased K⁺ concentration in shoots, resulting in a lowering of the Na⁺/K⁺ ratio by 30.5% and an increase in soluble sugar and soluble protein contents. Therefore, rhizosphere application of water-soluble and biodegradable γ-PGA facilitates the creation of an optimized rhizospheric environment for maize seedling and overcomes osmotic and ionic stresses, offering possibilities for future use in drip-irrigation systems in the cultivation of crops on saline-alkali land. Full article

The rapid increase in organic waste generation poses significant environmental challenges and highlights the limitations of conventional waste management practices. In this context, black soldier fly (Hermetia illucens) larvae (BSFL) have emerged as a promising biological tool for valorizing organic residues within circular bioeconomy frameworks. This review provides an integrated analysis of BSFL-based bioconversion systems, focusing on the biological characteristics of BSFL, suitable organic waste streams, and the key process parameters influencing waste reduction efficiency, larval biomass production, and frass (the residual material from larval bioconversion) yield. The performance of BSFL in converting organic waste is assessed with emphasis on substrate characteristics, environmental conditions, larval density, and harvesting strategies. Environmental and economic implications are discussed in comparison with conventional treatments such as landfilling, composting, and anaerobic digestion. Special attention is given to the nutritional composition of BSFL and the valorization of larvae as sustainable protein and lipid sources for animal feed and emerging human food applications, while frass is highlighted as a nutrient-rich organic fertilizer and soil amendment. Finally, current challenges related to scalability, safety, regulation, and social acceptance are highlighted. By linking waste management, resource recovery, and sustainable protein production, this review clarifies the role of BSFL and frass in resilient and resource-efficient food and waste management systems. Full article

Soil salinization leads to soil nutrient loss and decreased crop yield. This research aims to determine the optimal reduction rate of diammonium phosphate (DAP) and suitable microbial inoculant for alfalfa cultivation and nitrogen-level improvement in saline-alkali land. The experiment consisted of a factorial arrangement of three DAP fertilizer levels (X1, 60%; X2, 70%; and X3, 80%) and four microbial inoculants (Y1, rhizobial inoculant; Y2, phosphate-solubilizing microbial inoculant; Y3, composite microbial inoculant; and Y4, control) in a split-plot design. The results indicated that DAP fertilizer, microbial inoculant, and their interaction significantly affected (p < 0.05) forage yield, crude protein, available nitrogen (N), and enzyme activities. Under 80% DAP fertilizer combined with the composite microbial inoculant, forage yield, plant height, soil urease (S-UE), and ammonium nitrogen (NH₄⁺-N) reached maximum values of 17.1 t ha⁻¹, 65.7 cm, 292.3 μg d⁻¹ g⁻¹, and 3.1 mg kg⁻¹, respectively. However, the soil total nitrogen (TN) significantly increased at the 60% DAP fertilizer application rate (p < 0.05). Overall, this study demonstrates that co-application of DAP fertilizer with compound microbial inoculant delivers a green, science-based fertilization approach for improving nitrogen levels and alfalfa cultivation in saline-alkali soils. Full article

Saline soil represents an important reserve of cultivated land in China, yet poor soil conditions and low-nitrogen use efficiency constrain crop production. Biochar has been widely applied to improve soil properties; however, its interactive effects with nitrogen fertilization in saline soils remain unclear. A pot experiment using coastal saline soil collected from the northern Jiangsu province was conducted to evaluate the combined effects of biochar (0%, 4%, and 8% w·w⁻¹) and nitrogen fertilizer (0, 150, and 200 mg·kg⁻¹) on the growth performance, photosynthetic indices, yield, quality, and nitrogen use efficiency of water spinach (Ipomoea aquatica Forssk.). Moderate biochar application significantly improved vegetative growth of water spinach, as indicated by higher plant height, stem diameter, leaf area index, and SPAD values. In addition, biochar substantially enhanced photosynthetic performance, dry matter accumulation, and yield, whereas excessive biochar or nitrogen application generally inhibited plant performance. The combined application of 4% biochar with 150 mg·kg⁻¹ nitrogen consistently produced the highest yield and nitrogen partial factor productivity, while simultaneously increasing soluble protein, soluble sugar, and vitamin C contents and reducing nitrite accumulation. These research results demonstrated a clear synergistic interaction between biochar and nitrogen fertilization. In coastal saline soils, reducing the usage of nitrogen fertilizer moderately and adding approximately 4% of biochar is an effective strategy. Full article

Argania spinosa L. Skeels is an ecological pillar of the arid zones of South-West Morocco, currently threatened by the drastic climate change. This study investigates the effect of the combined application of compost (C) and subsurface water retention technology (SWRT) on field performances of one-(1Y) and two-year-old (2Y) argan seedlings. A randomized field trial was performed with four treatments: Control, C, SWRT, and C + SWRT. We evaluated soil properties, growth, and physiology, alongside biochemical parameters including stress markers, compatible solutes, antioxidant enzyme activities, and secondary metabolites. The results reveal the significant effect of C and/or SWRT on argan seedlings performances, particularly in 1Y subjects. The C + SWRT strongly stimulated stem elongation (246% vs. 163%), stomatal conductance (75% vs. 99%), photosynthetic efficiency (18% vs. 11%), and chlorophyll a content (80% vs. 65%) in 1Y and 2Y seedlings, respectively, compared to their corresponding controls. Under the same treatment, malondialdehyde levels were significantly reduced by 37% in 1Y seedlings and 23% in 2Y seedlings. In addition, catalase activity and soluble sugar, protein, and polyphenol content increased by 38, 43, 26, and 21%, respectively, in the younger seedlings and by 53, 51, 18, and 19%, respectively, in the elder seedlings. In terms of soil health, C + SWRT significantly enhanced total organic carbon and matter, available phosphorus, and reduced electrical conductivity. In summary, the C + SWRT application significantly improved argan plant performances, with a particularly marked effect on 1Y seedlings, which makes this combination an alternative solution to enhance the resilience of the argan tree in the era of climate change and promote the success of the reforestation program. Full article

White lupin (Lupinus albus) is a very important legume crop, having seeds with high protein content but also quantities of antinutritional alkaloids. Regarding cultivation, it is sensitive to neutral or alkaline soil conditions, although it is well adapted to drought conditions. In this study, the adaptability of 17 L. albus (14 commercial varieties and 3 advanced lines) genotypes to neutral-pH soils was investigated in relation to morphological, agronomical, and yield attributes. An extended characterization of seed composition for total alkaloids, trypsin inhibitors, phenolics, tannins, total nitrogen, NDF, ADF, and lignin was also performed. Furthermore, a prebreeding program consisting of 140 targeted crosses was initiated to develop new F1 combinations for genotypes with low alkaloid profiles; at the same time, controlled self-fertilization of elite lines was carried out. The results indicated that the morphological response of L. albus to neutral pH was positive and significantly genotypically dependent. Among the varieties tested, ‘Magnus’ and ‘Figaro’ showed low alkaloid and lignin contents. On the other hand, the advanced lines (LKAP, LKML, LKAU) had high antinutritional components, even though they were high-yielding. This research proposes a model of combined evaluation and selection processes for identification of particular genotypes that can perform well in neutral soils and provides the basis for breeding and producing low-alkaloid genotypes for multi-locational exploitation. Full article

The aim of the study was to investigate the effect of vegetation cover and height on soil and plant nutrients across managed and unmanaged agricultural land in a temperate climate. Fresh soil and vegetation samples were collected during the years 2023 and 2024 from 125 different land parcels in the southwest of the UK. Land was either managed for grazing and/or feed production or not managed for agricultural use, and had a range of grass, crop, legume, herb, and flower species. A linear mixed model was used to assess the effect of vegetation height (in cm) and cover (tonnes of dry matter per hectare) on soil and plant nutrients. The results showed plant dry matter (DM) digestibility, acid detergent fibre (ADF), water-soluble carbohydrate, and oil contents increased with vegetation height, and soil DM and neutral detergent fibre (NDF) decreased with vegetation height. The ratio of soil-to-plant OM reduced and ADF increased with increasing vegetation cover. Interactions between vegetation height and cover (i.e., density) were found for the ratio of soil-to-plant OM, ADF, NDF, DM, DM digestibility, oil, water-soluble carbohydrate, and crude protein nutrients. Measuring the interaction between soil and plant properties showed soil OM stocks increased and soil pH decreased with increased vegetation cover across agricultural land. Full article

Excessive application of chemical fertilisers has led to soil phosphorus immobilisation and aquatic eutrophication, making the development of highly efficient acid/neutral phosphatases crucial for sustainable phosphorus utilisation. In this study, we systematically investigated strain J2, which was isolated from phosphate-contaminated soil in Laoshan, Nanjing, China. 16S rRNA gene sequence analysis identified this strain as Acinetobacter nosocomialis J2, with 99.78% sequence similarity. Whole-genome sequencing generated a 3.83 Mb genome with a GC content of 38.59%, revealing multiple phospho-metabolism-related enzyme genes, including phospholipase C and α/β-hydrolases. A large language model–based protein representation learning strategy was employed to mine acid/neutral phosphatase genes from the genome, in which the model learned contextual and functional features from known phosphatase sequences and was used to identify semantically similar genes within the J2 genome. This approach predicted nine phosphatase candidate sequences, including AnACPase, a putative acid/neutral phosphatase. Biochemical characterisation showed that AnACPase exhibits optimal activity at pH 6.0 and 50 °C, with a K_m value of 0.2454 mmol/L for the p-NPP substrate, indicating high substrate affinity. Mn²⁺ and Ni²⁺ significantly enhanced enzyme activity, whereas Cu²⁺ and Zn²⁺ strongly inhibited it. Soil remediation experiments further validated the application potential of AnACPase, which solubilised 171.56 mg/kg of phosphate within seven days. Overall, this study highlights the advantages of deep learning-assisted genome mining for functional enzyme discovery and provides a novel technological pathway for the bioremediation of phosphorus-polluted soils. Full article

With intensifying global climate change and human activities, and with regional topography interactions, soil and water salinization has intensified, posing major ecological and environmental challenges worldwide. Here, we integrated histology, transmission electron microscopy, RNA sequencing (RNA-seq) and data-independent acquisition (DIA)-based proteomics to profile hepatopancreas responses of Exopalaemon carinicauda during acute sulfate stress (≤48 h). Sulfate exposure disrupted tubular architecture and organelle integrity, consistent with early cellular injury. Multi-omics analyses revealed metabolic reprogramming marked by suppressed glycolysis (e.g., HK2, ENO) and enhanced oxidative phosphorylation (e.g., ATP5F1B), together with activation of calcium signaling (e.g., SLC8A1, ADCY9) and reinforcement of antioxidant/one-carbon and glucose-branch pathways (e.g., SHMT2, PGAM2). These coordinated transcript–protein changes indicate a shift from rapid cytosolic ATP supply to mitochondrial ATP production while buffering Ca²⁺ overload and reactive oxygen species. Collectively, our results delineate the physiological and molecular adjustments that enable E. carinicauda to cope with sulfate conditions and provide mechanistic targets for selective breeding and water-quality management in saline–alkaline aquaculture. Full article

Microalgal amendments can improve soil structure by regulating extracellular polymeric substances (EPSs). However, the mechanisms underlying this process in red soils (characterized by high clay content and susceptibility to acidification) under different farming practices remain unclear. This study examined how Chlorella vulgaris (C. vulgaris) amendment influences EPS composition to enhance soil aggregate stability under arable land and rice paddy farming. A five-month pot experiment using a completely randomized design was conducted to investigate the effects of Chlorella vulgaris amendment on soils cultivated with Pennisetum × sinese and rice, two economically important crops commonly grown in South China. At the end of the experiment, Chlorella vulgaris amendment substantially increased both the mean weight diameter (MWD) and geometric mean diameter (GMD) of soil aggregates under both farming systems. Excitation–emission matrix (EEM) fluorescence spectroscopy revealed distinct changes in soil EPS components between the two farming types. Under arable land farming, humic-like and protein-like EPSs were dominant in Chlorella vulgaris-amended treatments, with fluorescence intensities more than doubling compared to the control. Conversely, under rice paddy farming, soil fulvic acid was the main component and showed a moderate increase. Partial least squares path modeling (PLS-PM) demonstrated that protein-like and humic-like EPSs had the strongest direct effects on aggregate stability in arable land red soil, while fulvic acid was the key factor in rice paddy red soil. The present study demonstrates that Chlorella vulgaris amendment improves aggregate stability in red soils through farming-specific, EPS-mediated pathways, providing a quantitative framework for researchers and land managers seeking to apply microalgal amendments for red soil enhancement and sustainable land management. Full article

Plant organic cation transporters (OCTs) are involved in a variety of beneficial biological processes, such as cadaverine transfer in plants and soil, and play an active role in the formation of plant stress resistance. In this study, 52 OCT family genes were identified in tomato, and comprehensive bioinformatics analyses of these numbers, such as promoter cis-acting elements, gene mapping and collinearity, protein characterization and phylogenetic analysis. By analyzing the expression of tomato OCT family genes under cold and salt stresses using transcriptome data and qRT-PCR experiments, a key gene regulating cold stress tolerance, SlOCT20, was identified. Subcellular localization experiments indicated that SlOCT20 was mainly localized in the cell membrane. When the SlOCT20 gene was silenced in tomato, the tolerance to cold stress was significantly reduced and oxidative stress was aggravated, indicating that this gene positively regulates the tolerance to cold stress in tomato. Full article

The dung beetle family Geotrupidae (Scarabaeoidea) plays a vital ecological role in nutrient cycling and soil health, yet the scarcity of complete mitochondrial genome (mitogenome) data has hindered phylogenetic and comparative studies within this family. Here, we sequenced, assembled, and annotated the first complete mitogenomes of Geotrupes stercorarius and Phelotrupes auratus, collected from the Qinghai–Tibetan Plateau. Comparative analysis of these two novel mitogenomes with eight existing mitogenomes revealed conserved architectural features across Geotrupidae, such as gene arrangement, tRNA secondary structures, and small intergenic spacers. Nucleotide composition was largely conserved, though marked divergence occurred at the third codon positions. Substantial structural variation was observed in non-coding regions, particularly in the control region and the nad2-trnW spacer. Evolutionary analyses indicated strong purifying selection across all protein-coding genes, with no evidence of widespread positive selection linked to high-altitude adaptation. Phylogenetic reconstruction consistently recovered the relationships (Bolboceratinae, (Lethrinae, Geotrupinae)), with Anoplotrupes and Geotrupes forming sister genera within Geotrupinae. This study provides additional mitogenomic resources and a well-supported phylogenetic framework for Geotrupidae, resolving key taxonomic uncertainties and establishing a basis for future evolutionary and ecological research. Full article

Root restriction is an agronomic technique that influences plant morphology, physiology, and productivity. This study investigates the effects of root restriction on tomato growth, fruit quality, yield, and rhizosphere microbial communities using three distinct substrates: sand, soil, and peanut shell substrate (PSS), within a Simplified Automatic Soilless Culture System (SAS). Results demonstrated that root restriction at 8 cm height significantly enhanced fruit quality indicators: soluble sugar content increased by 69.01% (sand), 53.84% (soil), and 37.67% (PSS); soluble protein increased by 77.23%, 48.14%, and 66.51%; and lycopene increased by 100.03%, 62.33%, and 74.59%, respectively, compared to the 24 cm baseline. However, single-plant yield declined by 28.30% (sand), 64.28% (soil), and 22.06% (PSS). TOPSIS analysis (Technique for Order Preference by Similarity to Ideal Solution) identified PSS at 8 cm as the optimal combination for balancing quality and yield (Cj = 0.631). Microbial amplicon sequencing revealed higher rhizosphere microbial diversity in tomatoes grown in soil and peanut shell substrate compared to sand. These three types of growing media (soil, sand, and peanut shell substrate) establish the rhizosphere of bacterial and fungal communities by selecting specific microbial taxa. Changes in container height drive the reduction–oxidation functional divergence of bacterial communities, affecting the connectivity and complexity of microbial networks. Full article

Plastic pollution is a major global challenge, especially nanoplastics (NPs) emerging as harmful pollutants due to their small size, reactivity, and persistence in ecosystems. Among them, cigarette butts composed of cellulose acetate (CA) are one of the most widespread and hazardous sources of terrestrial NPs. In this study, the immunotoxic, biochemical, and histopathological effects of cellulose acetate nanoplastics (CA-NPs) derived from smoked cigarette butts (SCB-NPs), unsmoked cigarette butts (USCB-NPs), and commercial cellulose acetate (CCA-NPs) were evaluated on the earthworm Allolobophora caliginosa. Adult worms were exposed for 30 days to 100 mg/kg CA-NPs in artificial soil under controlled laboratory conditions. Results revealed that SCB-NPs induced the most pronounced alterations, including increased lysozyme and metallothionein levels, reduced phagocytic and peroxidase activities, and depletion of protein and carbohydrate reserves. Histological examination showed vacuoles in epithelial layer vacuolization, space between muscle fiber disruption, and degeneration in gut and body wall, especially under SCB-NP exposure. USCB-NPs and CCA-NPs caused milder but still significant effects. Taken together, these findings highlight that the high toxicity of SCB-NPs is due to the presence of combustion-derived toxicants (nicotine, polycyclic aromatic hydrocarbons, and heavy metals), which exacerbate oxidative stress, immune suppression, and tissue damage in soil invertebrates. This study underscores the ecological risk of cigarette butt-derived NPs and calls for urgent policy measures to mitigate their terrestrial impacts. Full article