Search Results (8,296)

Arbuscular mycorrhizal fungi (AMF) and the antioxidant germanium (Ge) are promising tools for boosting bioactive compound synthesis and producing healthier foods. However, their combined effect remains unexplored. This study demonstrates the synergistic impact of AMF and Ge on the growth, metabolite accumulation, biological activities, and nutritional qualities of Spinacia oleracea L. (spinach), a globally significant leafy vegetable. Individually, Ge and AMF increased biomass by 68.1% and 22.7%, respectively, while their combined effect led to an 86.3% increase. AMF and Ge also improved proximate composition, with AMF–Ge interaction enhancing crude fiber and mineral content (p < 0.05). Interestingly, AMF enhanced photosynthesis-related parameters (e.g., total chlorophyll) in Ge treated plants, which in turn increased carbohydrate accumulation. This accumulation could provide a route for the biosynthesis of amino acids, organic acids, and fatty acids, as evidenced by increased essential amino acid and organic acid levels. Consistently, the activity of key enzymes involved in amino acids biosynthesis (e.g., glutamine synthase (GS), methionine biosynthase (MS), lysine biosynthase (LS)) showed significant increments. Furthermore, AMF improved fatty acid levels, particularly unsaturated fatty acids in Ge-treated plants compared to the control. In addition, increased phenylalanine provided a precursor for the production of antioxidants (e.g., phenols and flavonoids), through the action of the enzyme phenylalanine ammonia-lyase (PAL), resulting in improved antioxidant activity gains as indicated by FRAP, ABTS, and DPPH assays. This study is the first to show that Ge enhances the beneficial effect of AMF on spinach, improving growth and nutritional quality, with promising implications for agricultural practices. Full article

This study explores the production of bio-nutrients from bioactive compound-rich spent coffee grounds (SCG) and biochar (BC) through composting after inoculation with a biological agent and its impact on the growth performance of garden cress and spinach. The SCG was composted with six doses of BC (0, 5, 10, 15, 20, and 25%). The compost with 10% BC exhibited the best maturity, humification, and phytotoxicity index values of dissolved organic carbon (DOC), humification index (E4/E6), and germination index (GI). A metagenome analysis showed that compost starter enhanced the bacterial community’s relative abundance, richness, and diversity in SCG and BC treatments. This improvement included increased Patescibacteria, which can break down noxious phenolic compounds found in SCG and BC. The BC enriched the compost with phosphorus and potassium while preserving the nitrogen. In plant growth experiments, the total chlorophyll content in compost-treated garden cress and spinach was 2.47 and 4.88 mg g⁻¹, respectively, which was significantly greater (p ≤ 0.05) than in unfertilized plants and similar to the plants treated with traditional fertilizer. Overall, the results show that the compost of SCG + BC was well-suited for promoting the growth of garden cress and spinach, providing adequate nutrients as a fertilizer for these leafy vegetables. Full article

Drought represents a major environmental threat to global agricultural productivity. Employing plant growth-promoting rhizobacteria (PGPR) offers a promising strategy to enhance plant growth and resilience under drought stress. In this study, the strain G124, isolated from the arid region of Qinghai, was characterized at the molecular level, and its ability to enhance plant drought tolerance was validated through pot experiments. The findings revealed that the strain G124 belongs to Bacillus pacificus, with a 99.93% sequence similarity with B. pacificus EB422 and clustered within the same clade. Further analysis indicated that the strain G124 demonstrated a variety of growth-promoting characteristics, including siderophore production, phosphate solubilization, and the synthesis of indole-3-acetic acid (IAA), among others. Moreover, inoculation with B. pacificus G124 resulted in significant enhancements in plant height, leaf area, chlorophyll content, relative water content, and root development in both Arabidopsis thaliana and Medicago sativa seedlings under drought conditions. Additionally, G124 boosted antioxidant enzyme activities and osmolyte accumulation, while reducing malondialdehyde (MDA) and reactive oxygen species (ROS) levels in M. sativa seedlings exposed to drought. These findings suggest that B. pacificus G124 holds significant promise for enhancing plant drought tolerance and could be effectively utilized in crop management strategies under arid conditions. Full article

Eucalyptus plantations with fast growth and short rotation play an important role in improving economic conditions for local farmers and governments. It is necessary to map and update eucalyptus distribution in a timely manner, but to date, there is a lack of suitable approaches for quickly mapping its spatial distribution in a large area. This research aims to develop a uniform procedure to map eucalyptus distribution at a regional scale using the Sentinel-2 imagery on the Google Earth Engine (GEE) platform. Different seasonal Senstinel-2 images were first examined, and key vegetation indices from the selected seasonal images were identified using random forest and Pearson correlation analysis. The selected key vegetation indices were then normalized and summed to produce new indices for mapping eucalyptus distribution based on the calculated best cutoff values using the ROC (Receiver Operating Characteristic) curve. The uniform procedure was tested in both experimental and test sites and then applied to the entire Fujian Province. The results indicated that the best season to distinguish eucalyptus forests from other forest types was winter. The composite indices for eucalyptus–coniferous forest separation (CIEC) and for eucalyptus–broadleaf forest separation (CIEB), which were synthesized from the enhanced vegetation index (EVI), plant senescing reflectance index (PSRI), shortwave infrared water stress index (SIWSI), and MERIS terrestrial chlorophyll index (MTCI), can effectively differentiate eucalyptus from other forest types. The proposed procedure with the best cutoff values (0.58 for CIEC and 1.29 for CIEB) achieved accuracies of above 90% in all study sites. The eucalyptus classification accuracies in Fujian Province, with a producer’s accuracy of 91%, user’s accuracy of 97%, and overall accuracy of 94%, demonstrate the strong robustness and transferability of this proposed procedure. This research provided a new insight into quickly mapping eucalyptus distribution in subtropical regions. However, more research is still needed to explore the robustness and transferability of this proposed method in tropical regions or in other subtropical regions with different environmental conditions. Full article

Small-sized fish are a vital food source for large predatory commercial fish and play a key role in marine food webs, bridging lower and higher trophic levels. They are indispensable in maintaining the energy flow and material cycling within aquatic ecosystems. This study utilized bottom-trawl survey data from 2017 to 2020 along the south inshore of Zhejiang, China, complemented by concurrent environmental data, to examine the influence of environmental factors on the resource density and seasonal distribution patterns of four dominant small-sized fish species. The research findings indicated that SSH (sea surface height) and Chl (chlorophyll-a concentration) emerged as the key environmental factors influencing resource densities, with all four species exhibiting similar preferences toward these variables. However, significant disparities were observed in their preferences for SST (sea surface temperature), SSS (sea surface salinity), and DO (dissolved oxygen). The various species’ resource density and distribution patterns underwent significant seasonal variations. Additionally, the seasons and regions with the highest resource densities consistently aligned, occurring predominantly in autumn within the northern waters of the study area. This research further elucidated the environmental predilections and seasonal spatial distribution traits of small-sized fish in the south inshore of Zhejiang, an important feeding ground for economic fish species in the East China Sea. This provides scientific backing for forecasting alterations in coastal fishery resources under environmental and climate change scenarios and supports ecosystem-based fisheries management strategies. Full article

Potato–legume intercropping has been confirmed to increase productivity in modern agricultural systems. However, the physiological and ecological mechanisms of potato–soybean intercropping for promoting tuber yield formation in potato remain unclear. Field experiments were conducted in 2022 and 2023 to explore the responses of tuber yield formation, rhizosphere soil quality, root growth, and plant physiology of potato in potato–soybean intercropping. The soil at the experimental site is Cambisols. The treatments included sole cropping potato, sole cropping soybean, and potato–soybean intercropping. Our results indicated that potato –soybean intercropping decreased the water content, increased the total K content and activities of urease and catalase in rhizosphere soil, and enhanced the root mean diameter, root projected area, and root length density in the 0–5 cm and 15–20 cm soil layers of potato. Moreover, potato–soybean intercropping improved the plant photosynthetically active radiation and light transmittance rate of the middle and lower layers as well as the leaf area index, enhanced the leaf chlorophyll b content and ribulose-1,5-diphosphate carboxylase/oxygenase activity, and increased the leaf net photosynthetic rate and organ dry matter accumulation amounts of potato. The changes in the above parameters resulted in an increased tuber weight per plant (19.4%) and commercial tuber number (42.5%) and then enhanced the equivalent tuber yield of potato (38.2%) and land equivalent ratio (1.31 in 2022 and 1.33 in 2023). Overall, potato–soybean intercropping greatly increased the equivalent tuber yield by improving the rhizosphere soil quality, root growth, and plant physiology of potato and then achieved a higher land equivalent ratio. Full article

Soil autotoxic chemosensory substances have emerged as the predominant environmental factors constraining the growth, quality, and yield of Codonopsis pilosula in recent years. Among a vast array of chemosensory substances, benzoic acid constitutes the principal chemosensory substance in the successive cultivation of C. pilosula. However, the exploration regarding the stress exerted by benzoic acid on the growth and development of C. pilosula remains indistinct, and there is a scarcity of research on the mechanism of lobetyolin synthesis in C. pilosula. In the current research, it was discovered that exposure to benzoic acid at a concentration of 200 mmol/L conspicuously attenuated the plant height, root length, total length, fresh weight, root weight, root thickness, chlorophyll content, electrolyte osmolality, leaf intercellular CO₂ concentration (C_i), net photosynthesis rate (P_n), transpiration rate (T_r), and leaf stomatal conductance (G_s) of C. pilosula. Benzoic acid (200 mmol/L) significantly enhanced the activity of root enzymes, including superoxide dismutase (SOD), malondialdehyde (MDA), and peroxidase (POD), as well as the accumulation of polysaccharides and lobetyolins (polyacetylene glycosides) in the roots of C. pilosula. In this study, 58,563 genes were assembled, and 7946 differentially expressed genes were discovered, including 4068 upregulated genes and 3878 downregulated genes. The outcomes of the histological examination demonstrated that benzoic acid stress augmented the upregulation of genes encoding key enzymes implicated in the citric acid cycle, fatty acid metabolism, as well as starch and sucrose metabolic pathways. The results of this investigation indicated that a moderate amount of benzoic acid could enhance the content of lobetyolin in C. pilosula and upregulate the expression of key coding genes within the signaling cascade to improve the resilience of C. pilosula lobetyolin against benzoic acid stress; this furnished a novel perspective for the study of C. pilosula lobetyolin as a potential substance for alleviating benzoic acid-induced stress. Full article

Estimating leaf chlorophyll content (LCC) in a timely manner and accurately is of great significance for the precision management of rape. The spectral index derived from UAV images has been adopted as a non-destructive and efficient way to map LCC. However, soil background impairs the performance of UAV-based LCC estimation, limiting the accuracy and applicability of the LCC estimation model, and this issue remains to be addressed. Thus, this research was conducted to study the influence of soil pixels in UAV RGB images on LCC estimation. UAV campaigns were conducted from overwintering to flowering stages to cover the process of soil background being gradually covered by rapeseed plants. Three planting densities of 11.25, 18.75, and 26.26 g/m² were chosen to further enrich the different soil background percentage levels, namely, the rape fractional vegetation coverage (FVC) levels. The results showed that, compared to the insignificant difference observed for the ground measured LCC at a certain growth stage, a significant difference was found for most of the spectral indices extracted without soil background removal, indicating the influence of soil background. Removing soil background during the extraction of the spectral index enhanced the LCC estimation accuracy, with the coefficient of determination (R²) increasing from 0.58 to 0.68 and the root mean square error (RMSE) decreasing from 5.19 to 4.49. At the same time, the applicability of the LCC estimation model for different plant densities (FVC levels) was also enhanced. The lower the planting density, the greater the enhancement. R² increased from 0.53 to 0.70, and the RMSE decreased from 5.30 to 4.81 under a low planting density of 11.25 g/m². These findings indicate that soil background removal significantly enhances the performance of UAV-based rape LCC estimation, particularly under various FVC conditions. Full article

Endophytic fungi inhabit various plant tissues and organs without inducing evident disease symptoms. They can contribute positively to the growth of plants, bolster plants resilience to environmental and biological stresses, and facilitate the accumulation of secondary metabolites. These microbial resources possess significant developmental and utilization value in various applications. Hence, this study focused on exploring the plant growth-promoting (PGP) traits of 14 endophytic fungi from Ligusticum chuanxiong Hort (CX) and elucidating the effects and mechanisms that facilitate plant growth. According to PGP activity evaluation, the majority of strains demonstrated the capacity to produce IAA (78.57%), siderophores (50.00%), ammonia (35.71%), potassium solubilization (21.43%), nitrogen fixation (57.14%), and phosphate solubilization (42.86%). Further investigations indicated that the levels of IAA ranged from 13.05 to 301.43 μg/mL, whereas the soluble phosphorus levels ranged from 47.32 to 125.95 μg/mL. In cocultivation assays, it was indicated that Fusarium sp. YMY5, Colletotrichum sp. YMY6, Alternaria sp. ZZ10 and Fusarium sp. ZZ13 had a certain promoting effect on lateral root number and fresh weight of tobacco. Furthermore, ZZ10 and ZZ13 significantly enhanced the germination potential, germination index, and vigor index of tobacco seeds. The subsequent potted trials demonstrated that the four endophytic fungi exhibited an enhancement to growth parameters of tobacco to a certain extent. ZZ10 and ZZ13 treatment had the best promotion effect. Inoculation with YMY5 increased the chlorophyll a and total chlorophyll content. ZZ10 and ZZ13 treatment remarkably increased the net photosynthetic rate, soluble sugars and soluble protein content, catalase and peroxidase activities, and lowered malondialdehyde content in tobacco leaves. In addition, YMY5 remarkably elevated superoxide dismutase activities. ZZ13 upregulated the expression of growth-related gene. Among them, ZZ13 had a better growth-promoting effect. In conclusion, these endophytic fungi possessing multi-trait characteristics and the capacity to enhance plant growth exhibit promising potential as biofertilizers or plant growth regulators. Full article

Soil salinity significantly impacts crop productivity. In response, plant growth-promoting rhizobacteria (PGPR) offer an innovative and eco-friendly solution to mitigate salinity stress. However, research on PGPR’s effects on crop physiology under varying salinity levels is still emerging. This study evaluates the impact of five bacterial strains, isolated from compost, on the growth of maize (Zea mays) and tomato (Solanum lycopersicum) plants under different levels of salt stress. This study involved treating maize and tomato seeds with five bacterial strains, and then planting them in a greenhouse under varying salt stress conditions (43 mM, 86 mM, 172 mM, 207 mM NaCl) using a Randomized Complete Block Design. Results showed that bacterial inoculation improved plant growth under saline conditions. S2015-1, S2026-2, and S2027-2 (Bacillus cereus, Acinetobacter calcoaceticus, Bacillus subtilis) were particularly effective in promoting plant growth under salt stress, especially at ionic concentrations of 43 mM and 86 mM, leading to a substantial increase in fresh and dry weight, with strain S2015-1 boosting chlorophyll by 29% at 86 mM in both crops. These results highlight the potential of PGPR to enhance crop resilience and productivity under salinity stress, promoting climate-smart agricultural practices. Full article

The remote sensing of sun-induced chlorophyll fluorescence (SIF) is an emerging technique with immense potential for terrestrial vegetation sciences. However, the interpretation of fluorescence data is often hindered by the complexity of observed land surfaces. Therefore, advanced remote sensing models, particularly physically based simulations, are critical to accurately interpret SIF data. In this work, we propose a three-dimensional (3D) radiative transfer model that employs the Monte Carlo ray-tracing technique to simulate the excitation and transport of SIF within plant canopies. This physically based approach can quantify the various radiative processes contributing to the observed SIF signal with high fidelity. The model’s performance is rigorously evaluated by comparing the simulated SIF spectra and angular distributions to field measurements, as well as conducting systematic comparisons with an established radiative transfer model. The results demonstrate the proposed model’s ability to reliably reproduce the key spectral and angular characteristics of SIF, with the coefficient of determination (R2) exceeding 0.98 and root mean square error (RMSE) being less than 0.08 mW m⁻² sr⁻¹ nm⁻¹ for both the red and far-red fluorescence peaks. Furthermore, the model’s versatile representation of canopy structures, enabled by the decoupling of radiation and geometry, is applied to study the impact of 3D structure on SIF patterns. This capability makes the proposed model a highly attractive tool for investigating SIF distributions in realistic, heterogeneous canopy environments. Full article

Against the backdrop of climate change, soil loss, and water scarcity, sustainable food production is a pivotal challenge for humanity. As the global population grows and urbanization intensifies, innovative agricultural methods are crucial to meet rising food demand, while mitigating environmental degradation. Hydroponic and aquaponic systems, has emerged as one of these solutions by minimizing land use, reducing water consumption, and enabling year-round crop production in urban areas. This study aimed at assessing the yield, ecophysiological performance, and nutritional content of Lactuca sativa L. and Cichorium endivia L. var. crispum grown in hydroponic and aquaponic floating raft systems, with Oreochromis niloticus L. integrated into the aquaponic system. Both species exhibited higher fresh biomass and canopy/root ratios in hydroponics compared to aquaponics. Additionally, hydroponics increased the leaf number in curly endive by 18%. Ecophysiological parameters, such as the leaf net photosynthesis rate, actual yield of PSII, and linear electron transport rate, were also higher in hydroponics for both species. However, the nutritional profiles varied between the two cultivation systems and between the two species. Given that standard fish feed often lacks sufficient potassium levels for optimal plant growth, potassium supplementation could be a viable strategy to enhance plant development in aquaponic systems. In conclusion, although aquaponic systems may demonstrate lower productivity compared to hydroponics, they offer a more sustainable and potentially healthier product with fewer harmful compounds due to the reduced use of synthetic fertilizers, pesticides, and the absence of chemical residue accumulation. However, careful system management and monitoring are crucial to minimize potential contaminants. Full article

The exploitation of drought is a critical worldwide challenge that influences wheat growth and productivity. This study aimed to investigate a synergistic amendment strategy for drought using the single and combined application of plant growth-promoting microorganisms (PGPM) (Trichoderma harzianum) and biogenic silica nanoparticles (SiO₂NPs) from rice husk ash (RHA) on Saudi Arabia’s Spring wheat Summit cultivar (Triticum aestivum L.) for 102 DAS (days after sowing). The significant improvement was due to the application of 600 ppm SiO₂NPs and T. harzianum + 600 ppm SiO₂NPs, which enhanced the physiological properties of chlorophyll a, carotenoids, total pigments, osmolytes, and antioxidant contents of drought-stressed wheat plants as adaptive strategies. The results suggest that the expression of the studied genes (TaP5CS1, TaZFP34, TaWRKY1, TaMPK3, TaLEA, and the wheat housekeeping gene TaActin) in wheat remarkably enhanced wheat tolerance to drought stress. We discovered that the genes and metabolites involved significantly contributed to defense responses, making them potential targets for assessing drought tolerance levels. The drought tolerance indices of wheat were revealed by the mean productivity (MP), stress sensitivity index (SSI), yield stability index (YSI), and stress tolerance index (STI). We employed four databases, such as BAR, InterPro, phytozome, and the KEGG pathway, to predict and decipher the putative domains in prior gene sequencing. As a result, we discovered that these genes may be involved in a range of important biological functions in specific tissues at different developmental stages, including response to drought stress, proline accumulation, plant growth and development, and defense response. In conclusion, the sole and/or dual T. harzianum application to the wheat cultivar improved drought tolerance strength. These findings could be insightful data for wheat production in Saudi Arabia under various water regimes. Full article

Remote sensing has proven to be a vital tool for monitoring and forecasting the quality and yield of crops. The utilization of innovative technologies such as Solar-Induced Fluorescence (SIF) and satellite measurements of column-averaged CO₂ (xCO₂) can enhance these estimations. SIF is a signal emitted by crops during photosynthesis, thus indicating photosynthetic activities. The concentration of atmospheric CO₂ is a critical factor in determining the efficiency of photosynthesis. The aim of this study was to investigate the correlation between satellite-derived Solar-Induced Chlorophyll Fluorescence (SIF), column-averaged CO₂ (xCO₂), and Normalized Difference Vegetation Index (NDVI) and their association with sugarcane yield and sugar content in the field. This study was carried out in south-central Brazil. We used four localities to represent the region: Pradópolis, Araraquara, Iracemápolis, and Quirinópolis. Data were collected from orbital systems during the period spanning from 2015 to 2016. Concurrently, monthly data regarding tons of sugarcane per hectare (TCH) and total recoverable sugars (TRS) were gathered from 24 harvest locations within the studied plots. It was observed that TRS decreased when SIF values ranged between 0.4 W m⁻² sr⁻¹ μm⁻¹ and 0.8 W m⁻² sr⁻¹ μm⁻¹, particularly in conjunction with NDVI values below 0.5. TRS values peaked at 15 kg t⁻¹ with low NDVI and xCO₂ values, alongside SIF values lower than 0.4 W m⁻² sr⁻¹ μm⁻¹ and greater than 1 W m⁻² sr⁻¹ μm⁻¹. These findings underscore the potential of integrating SIF, xCO₂, and NDVI measurements in the monitoring and forecasting of yield and sugar content in sugarcane crops. Full article

Drought stress is one of the main abiotic stresses that limit plant growth and affect fruit quality and yield. Plants primarily lose water through leaf transpiration, and wax effectively reduces the rate of water loss from the leaves. However, the relationship between water loss and the wax formation mechanism in goji (Lycium barbarum) leaves remains unclear. ‘Ningqi I’ goji and ‘Huangguo’ goji are two common varieties. In this study, ‘Ningqi I’ goji and ‘Huangguo’ goji were used as samples of leaf material to detect the differences in the water loss rate, chlorophyll leaching rate, wax phenotype, wax content, and components of the two materials. The differences in wax-synthesis-related pathways were analyzed using the transcriptome and metabolome methods, and the correlation among the wax components, wax synthesis genes, and transcription factors was analyzed. The results show that the leaf permeability of ‘Ningqi I’ goji was significantly lower than that of ‘Huangguo’ goji. The total wax content of the ‘Ningqi I’ goji leaves was 2.32 times that of the ‘Huangguo’ goji leaves, and the epidermal wax membrane was dense. The main components of the wax of ‘Ningqi I’ goji were alkanes, alcohols, esters, and fatty acids, the amounts of which were 191.65%, 153.01%, 6.09%, and 9.56% higher than those of ‘Huangguo’ goji, respectively. In the transcriptome analysis, twenty-two differentially expressed genes (DEGs) and six transcription factors (TFs) were screened for wax synthesis; during the metabolomics analysis, 11 differential metabolites were screened, which were dominated by lipids, some of which, like D-Glucaro-1, 4-Lactone, phosphatidic acid (PA), and phosphatidylcholine (PE), serve as prerequisites for wax synthesis, and were significantly positively correlated with wax components such as alkanes by the correlation analysis. A combined omics analysis showed that DEGs such as LbaWSD1, LbaKCS1, and LbaFAR2, and transcription factors such as LbaMYB306, LbaMYB60, and LbaMYBS3 were strongly correlated with wax components such as alkanes and alcohols. The high expression of DEGs and transcription factors is an important reason for the high wax content in the leaf epidermis of ‘Ningqi I’ goji plants. Therefore, by regulating the expression of wax-synthesis-related genes, the accumulation of leaf epidermal wax can be promoted, and the epidermal permeability of goji leaves can be weakened, thereby reducing the water loss rate of goji leaves. The research results can lay a foundation for cultivating drought-tolerant goji varieties. Full article