Chemical and Biological Technologies in Agriculture最新文献

Sorghum is a vital economic crop in China, generating substantial amounts of crop residues annually, which necessitates research into its comprehensive utilization. Cyanogenic glycosides, a class of metabolites widely distributed in sorghum and other plant species, tend to release hydrogen cyanide under enzymatic action, posing a potential poisoning risk to animals. In the present study, to enhance the fermentation quality of sorghum straw silage, β-glucosidase-producing lactic acid bacteria isolated from fresh sorghum straw were employed as inoculants. A systematic investigation was conducted on the microbial community structure and metabolomic profiles following 60 days of fermentation, utilizing untargeted metabolomics analysis to elucidate the mechanisms by which β-glucosidase-producing lactic acid bacteria influence sorghum straw silage fermentation quality, as well as the degradation of dhurrin and reduction of hydrocyanic acid levels in sorghum. The results demonstrated that the silage fermentation quality in the lactic acid bacteria-supplemented experimental group was significantly improved compared to the control group. Attributed to the modulation of metabolic pathways, the levels of dhurrin and hydrocyanic acid exhibited a significant decrease with extended ensiling duration. At the metabolite level, biological pathways involved in steroid biosynthesis, terpenoid synthesis, and carotenoid synthesis were upregulated during different stages of ensiling. These metabolites not only enhance the nutritional value of the feed, but also possess anti-inflammatory and health-promoting properties, thereby further underscoring the positive regulatory role of lactic acid bacteria in the silage process.

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The role of polymeric hydrogel (PMH) in wheat's response to Benzo[a]pyrene (BaP) stress is acknowledged, although mechanisms involved are not fully understood and have never reported. The present research found that exposure to BaP stress fast increased endogenous jasmonic acid levels in wheat roots. Polymeric hydrogel alleviated BaP toxicity by reducing BaP absorption in shoot cell walls and roots, accomplished through up-regulation of BaP chelation and efflux-associated genes like OsCAL1, OsABCG36 and OsHMA3, while concurrently down-regulating transcript degrees of BaP uptake and translocation-associated genes, such as OsZIP5/7, OsNRAMP1/5, OsCCX2 and OsHMA2. A decrease in hemicellulose levels was noted in cell wall of roots. The mitigating effect of polymeric hydrogel on BaP accumulation depended on the inhibition of nitric oxide production, as the nitric oxide donor SNP may diminish this effect. In brief, polymeric hydrogel significantly lowered BaP levels in wheat by downregulating cell wall's ability to absorb BaP, likely by decreasing nitric oxide generation.

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Improper disposal of jackfruit peel waste poses environmental risks, but its polysaccharides (PJP) offer potential health benefits. This study aimed to optimize the ultrasound-microwave-assisted extraction conditions for PJP and evaluate their structural characteristics as well as intestinal health activity. Using Box–Behnken design, the optimal extraction yield of 24.6% was achieved under the following conditions: solid-to-liquid ratio of 48.7 mL/g, extraction time of 29.8 min, and extraction temperature of 81.9 °C. Structural analysis revealed that PJP primarily consists of glucose units with a backbone linked by → 4)-β-D-Glcp-(1 →. In DSS-induced colitis mice, PJP increased the abundance of intestinal microorganisms (Bacteroides and Lactobacillus), enhanced the production of short-chain fatty acids (SCFAs), and reduced inflammation (TNF-α, IL-1β), while enhancing the levels of tight junction proteins (claudin-1, occludin, ZO-1). This study provides a methodological framework for polysaccharide research and provides preliminary evidence for the industrial production and practical application of PJP.

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Organic pollution, particularly persistent organic pollutants (POPs), pose significant threats to the natural environment and human health. Bioremediation, especially phytoremediation, has emerged as a promising approach for degrading organic pollutants due to its cost-effectiveness and environmental sustainability. Legumes are widely used in phytoremediation because of their well-developed root systems and symbiotic rhizosphere microorganisms. This review provides a comprehensive overview of the efficiency and mechanisms of legume-based phytoremediation, along with the role of auxiliary additives in addressing organic pollution. These additives include microorganisms, other plants, and additional substances (including bioactive substances, secondary metabolites and inactive additives). Legumes can effectively increase degradation rates, especially for pesticides and polycyclic aromatic hydrocarbons (PAHs), across various timeframes (15–180 days) and environmental conditions (water, synthetic soil, or field soil). Auxiliary additives further facilitate this process through different mechanisms. Intercropping systems that integrate legumes with other plants promote soil health and enable gradual yet cost-effective biodegradation. Microorganisms and plants can work synergistically to achieve co-degradation through three potential pathways, while additional substances contribute to soil health and simultaneously enhance pollutant biodegradation. Each of these approaches offers specific advantages. Additionally, a sustainable cycle involving legumes, crops, and additional substances could be established for long-term reuse. These findings provide valuable evidence and guidance for legume-based phytoremediation, offering insights and hypotheses for future research on biodegradation mechanisms.

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Background

Microbial seed coating is an effective method to improve seed performance and alleviate salt stress. However, insufficient microbial survival rate and short storage period are the key factors limiting the use of microbial seed coating agents.

Methods

In this study, we screened a growth-promoting functional strain from wheat rhizosphere. This strain was encapsulated within potassium alginate (A)/pectin (P) microcapsules to develop a microbial seed coating agent. The encapsulation process was optimized to achieve high efficiency, and the resulting microcapsules were evaluated for storage stability. Coated seeds were tested under salt stress (mild and severe) conditions to assess germination rates, biomass accumulation, root growth, chlorophyll content, antioxidant enzyme activities (superoxide dismutase, catalase, and peroxidase), oxidation markers (hydrogen peroxide and malondialdehyde), and plant hormones (auxin, gibberellin, abscisic acid, and cytokinin).

Results

Functional strain (Pseudoxanthomonas suwonensis) isolated from wheat rhizosphere have the ability to produce auxin, catalase and siderophores. The embedding rate of A/P microcapsules reached 79.67% after optimization. After 28 days of storage, compared with the control (uncoated bacteria), the survival rate of microcapsules was significantly increased by 27.96%. Under salt stress, compared with the blank control, A/P-coated seeds increased the germination rate (up to 18.33%), biomass and root growth. The chlorophyll content and activity levels of antioxidant enzymes (peroxidase, catalase, and superoxide dismutase) increased by 19.86–66.07%, 6.64–13.52%, 5.35–5.41%, and 2.28%, respectively. The contents of hydrogen peroxide and malondialdehyde decreased by 4.39% and 9.29–18.42%, respectively, the auxin, gibberellin, and cytokinin levels in wheat significantly increased by 8.06–9.68%, 8.32%, and 12.93–20.72%, respectively.

Conclusions

This study demonstrates that A/P microcapsules effectively enhance the survival and functionality of P. suwonensis as a seed coating agent, significantly improving wheat's salt stress tolerance. The microencapsulated coating prolongs microbial viability during storage while promoting plant growth through biochemical mechanisms, providing an effective microbial coating carrier for crops under salt stress in agricultural production.

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Background

Iron (Fe) deficiency in agricultural soils significantly affects crop productivity and quality. The application of synthetic Fe chelates is a common agricultural practice to address this issue, as they can maintain Fe solubility across a wide pH range. However, Fe chelates are susceptible to photodegradation, reducing their effectiveness, especially in hydroponic crops using UV radiation disinfection systems. This study aims to investigate the photodegradation behavior of six Fe chelates: classified as non-phenolic (EDTA, [S,S’]-EDDS, and IDHA) and phenolic (o,oEDDHA, HBED, and EDDHSA) agents, using a designed robust compact photocatalytic system with TiO₂ under UV irradiation. The objective is to establish a straightforward and reliable methodology for predicting the photochemical behavior of Fe chelates in hydroponic cultivation systems.

Results

A Central Composite Design (CCD) was applied to establish the best experimental conditions. Kinetic parameters (order, rate constants and half-life) were determined in selected conditions, showing that both groups of chelates degrade differently under the conditions studied. In general, non-phenolic chelates showed faster degradation, while phenolic chelates, mainly o,oEDDHA/Fe³⁺ and EDDHSA/Fe³⁺, exhibited greater stability. The presence of macronutrients as well as copper slightly modified the photodegradation in a model nutrient solution, except for the chelate [S,S’]-EDDS/Fe³⁺, that is completely degraded. Despite TiO₂ enhancing photodegradation, degradation rates are low enough in short times exposure to permit the reutilization of Fe chelates in recycled hydroponic systems.

Conclusions

The study demonstrates that the photodegradation rates of Fe chelates vary significantly between non-phenolic and phenolic agents, with the latter showing greater resistance to degradation under UV light in the TiO₂-based photocatalytic system. The developed compact photocatalytic system has proven to be an effective tool for predicting the photochemical stability of Fe chelates, offering valuable insights for optimizing their use in soilless growing systems.

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Background

Dynamic elements including carbon (C), nitrogen (N), phosphorus (P), and sulfur (S), in soil are distinguished by significant geographical heterogeneity. Despite the decisive role that soil nutrients have in regulating the processes in a terrestrial ecosystem, their spatial distribution and stoichiometric relationships remain poorly understood across different geographical regions. This lack of detailed knowledge limits our ability to accurately assess ecosystem productivity and nutrient dynamics. The present study addresses this critical gap by examining the spatial variability and stoichiometry of soil organic carbon (SOC) and key soil nutrients (N, P, S), including their elemental ratios (C:N, C:P, C:S). This research aims to investigate the spatial distribution and stoichiometric ratios of these essential elements. By understanding these patterns, this study will provide insights for enhancing health of soil, boosting fertility, and guiding better agricultural interventions in the studied regions.

Location

In the present study, an overall of 1440 samples of 16 benchmark soils were collected from rice–wheat, cotton–wheat, maize–wheat, and fallow–wheat cropping areas of the Punjab province, Pakistan.

Methods

The collected samples were fractionated and studied for total SOC, N, S, and P quantification. The degree of spatial dependence and geographical patterns of C, P, N, S contents and their ratios in the studied cropping systems were then assessed.

Results

The average amount of SOC, total N, P and S varied from 224.7–355.7, 20.3–29.4, 5.1–6.6 and 4.1–5.5 mmol/kg under the studied cropping systems of Punjab. Semi-variogram modeling depicted the strong spatial dependency for C, S, N, and P, while a moderate fluctuation was seen for C:N, C:P and C:S ratios in the order of fallow–wheat (FW) > rice–wheat (RW) > cotton–wheat (CW) > maize–wheat (MW) cropping systems. High spatial variability was found in FW compared to CW, MW and RW cropping systems. Moreover, a consistent stoichiometric C:N:P:S ratio of 62.2:5.4:1.2:1, was explored across the studied benchmark soil series under various cropping systems of the Punjab. SOC revealed a strong correlation with N, P, S concentration and C:P, C: N, and C:S ratios in soil.

Conclusions

A better understanding of the spatial variability for C, N, P, S concentrations and C:N, C:P, C:S ratios is useful for increasing carbon storage by managing C:N:P:S stoichiometry and refining agricultural management practices which ultimately improves soil health.

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Salvia dominica L. is a fragrant perennial shrub densely adorned with trichomes, found throughout the eastern Mediterranean, especially Palestine, Jordan, Lebanon and Syria. It is commonly used by the Bedouins for the remedy of many diseases. In recent years, essential oils (EOs) have attracted interest due to their biological qualities. This study sought to examine the chemical composition of EOs extracted from the dry and fresh leaves of Salvia dominica L. and to evaluate their in vitro antioxidant, anticancer, antibacterial and α-amylase and lipase inhibitory activity. The chemical compositions of EOs obtained by steam distillation were determined using gas chromatography–mass spectrometry. The principal constituents of the oil derived from fresh Salvia dominica L. leaves comprised linalyl acetate (43.69%), α-terpinyl acetate (12.35%), germacrene D (10.22%), linalool (9.40%), 1,8-cineole (7.07%), and α-terpineol (4.97%), with the predominant category being oxygenated monoterpenes (OM) at 74.60%. The principal constituents of the EO obtained from air-dried leaves included linalyl acetate (70.17%), germacrene D (10.20%), terpinyl acetate (7.49%), and 1,8-cineole (4.08%), with oxygenated monoterpenes (OM) representing the predominant class at 80.87%. The air-dried flowers of Salvia dominica L. were extracted with CO₂–CH₂Cl₂, yielding a dark brown sticky oil that was fractionated into five fractions via silica gel chromatography. Interestingly, fractions (F3 and F4) showed significant anticancer activity against MCF-7 and HeLa cell lines, with IC₅₀ values ranging from 25.41 ± 1.27 to 40.94 ± 2.05 μg/mL, while both EOs showed reduced anticancer properties and poor α-amylase and lipase activities. Both EOs displayed outstanding antioxidant activity, and modest antibacterial activity against K. pneumonia and S. aureus with MIC values between 0.39 and 3.125 μL/mL. The fractions 4 and 5 of the CO₂ extract showed enhanced antibacterial efficacy relative to the commonly employed antibiotic gentamicin (31.25–125 µg/mL) against all tested microorganisms, with MIC values between 6.25 and 25 µg/mL.

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Background

Poly-3-hydroxybutyrate (P3HB) is a biodegradable plastic that may affect soil quality and plant growth. To explain the observed deterioration of plant growth, this study investigated the effects of P3HB microplastics on the soil microbiome and its activity related to content of nutrients and their transformation processes. A pot experiment was conducted using soil contaminated with five different doses of P3HB, both with and without maize. Soil mineral nitrogen forms, microbial properties as well as plant biomass were determined.

Results

P3HB significantly altered soil properties by stimulating microbial respiration, enhancing carbon turnover, and shifting nitrogen forms, notably reducing NO₃⁻ availability. The fungal community was more sensitive to P3HB compared to the bacterial one. Fungal genera such as Tetracladium, Exophiala, and Pseudogymnoascus were stimulated; others such as Gibberella and Gibellulopsis declined. In the bacterial community, P3HB promoted the growth of copiotrophic P3HB degraders (e.g., Actinobacteria, Alphaproteobacteria); increased the abundance of anaerobes (Clostridia); decreased nitrifying groups (Nitrososphaeria, Nitrospiria); and reduced oligotrophic taxa (Vicinamibacteria, Thermoleophilia). These changes led to altered nutrient cycling, including inhibited nitrification and reduced mineral nitrogen availability, contributing to decreased maize growth.

Conclusions

Soil contamination with ≥ 1% P3HB microplastics disrupts microbial structure and nutrient dynamics, with potential negative effects on soil fertility and plant productivity.

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Background

Nanozymes are a class of nanocatalytic materials that mimic the functions of natural enzymes. Their enzyme-like properties enable the catalytic scavenging of excess reactive oxygen species (ROS) generated in plants under abiotic stress, thereby alleviating oxidative stress. Research on nanozymes’ role and related mechanisms in alleviating low-temperature stress in crops is still unclear. Therefore, developing nanozymes that enhance early stage cold tolerance in crops is critical for maintaining agricultural production and global food security.

Results

We synthesized a nanozyme with catalase (CAT)-like activity, manganese-doped cerium oxide (MCNPs) nanoparticles. This study demonstrates that priming with MCNPs significantly accelerated wheat germination under cold stress, increasing the germination index by 7.1% and seedling biomass by 6.2–17.2% compared to hydropriming. Through SP–ICP–MS analysis, we confirmed that MCNPs can enter the seed. We also found that the catalase-like activity of MCNPs synergistically enhanced endogenous antioxidant enzymes (CAT and superoxide dismutase) to effectively eliminate excessive ROS in wheat seeds. Further analysis using LC–MS and qPCR showed that this ROS homeostasis influenced hormone metabolism by regulating the expression of genes involved in the hormone metabolic network, elevating growth-promoting hormones (gibberellin and ethylene) by 25.5–27.2% while suppressing stress-responsive hormones (jasmonic acid and abscisic acid). Subsequent activation of the gibberellin-responsive transcription factor TaGAMYB up-regulated amylase genes, boosting β-amylase activity by 17.1–18.5% and accelerating starch hydrolysis into reducing sugars, collectively enhancing low-temperature germination.

Conclusions

MCNP priming significantly alleviated the inhibitory effects of low temperature on wheat seed germination by coordinately regulating the processes of “ROS homeostasis,” “hormone metabolism,” and “starch hydrolysis,” offering a promising strategy for enhancing plant cold tolerance and maintaining food security in the face of climate change.

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