Chemical and Biological Technologies in Agriculture最新文献

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.

Graphical abstract

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.

Graphical Abstract

Background

Carbon metabolism in plants involves biochemical processes such as photosynthesis, respiration, and carbon partitioning. This study aimed to elucidate the physiological and biochemical dynamics during the early development of pea seedlings (Pisum sativum) across five time points (6, 9, 12, 15, and 18 days) and five cultivars (Dacheong, Daehyeop 1ho, Sanghyeop, Sacheol, and Cheongmi) using semi-targeted metabolic profiling. Furthermore, we investigated the interplay between photosynthetic activity and secondary metabolite accumulation by profiling the metabolic responses of Dacheong seedlings exposed to varying photosynthetic photon flux densities (PPFDs).

Results

A total of 83 metabolites were identified. Multivariate analysis revealed similar biochemical dynamics among the five cultivars during the early seedling stage. Metabolic shifts occurred in three distinct phases: (1) an early nitrogen-rich storage metabolism phase characterized by the accumulation of asparagine and raffinose, (2) an intermediate phase marked by the accumulation of branched-chain amino acids, flavonoids, and carotenoids, and (3) a late phase characterized by increased monosaccharides and chlorophylls. These findings suggest that seedling growth relies on the mobilization and conversion of carbohydrates stored in seeds prior to the development of photosynthetic organs. Notably, significant correlations were observed between the photosynthetic pigments and secondary metabolites. Among the cultivars, Dacheong (12 days) exhibited the highest total flavonoid content (33.40 ± 1.29 mg/g). The metabolic changes in Dacheong seedlings under varying PPFD conditions indicated that higher light intensity enhanced sucrose synthesis and chloroplast component composition. Additionally, carotenoid and flavonoid levels peaking at PPFD 400 µmol/m²·s suggested that this light intensity is the optimal condition for maximizing secondary metabolite accumulation through enhanced photosynthetic activity.

Conclusions

This study is the first to profile the transition from heterotrophic to autotrophic growth in pea seedlings and reveal significant correlations between photosynthetic pigments and secondary metabolites during the seedling period. These findings provide insights into metabolic reprogramming in pea seedlings and inform strategies for enhancing their growth and nutritional quality. Future studies should include hormone analyses to further understand the metabolic transition processes in seedlings.

Graphical Abstract

Background

Post-harvest browning in Lanzhou lily scales is a major challenge to quality maintenance and industrial advancement. Traditional preservation methods face challenges of high costs and chemical residues. Hydrogen gas (H₂), as an emerging preservative, offers significant advantages, including environmental friendliness and high efficacy in microbial inhibition. However, the anti-browning mechanism of H₂ remains unclear.

Results

H₂ fumigation was found to effectively delay the decline in firmness and reduce fresh weight loss in lily scales, with the most significant browning inhibition observed on day 6. In addition, H₂ fumigation increased the content of soluble sugars and soluble proteins while decreasing the content of total phenols. Metabolomic and transcriptomic analyses demonstrate that differentially expressed genes (DEGs) and differential metabolites (DAMs) were significantly enriched in pathways related to enzymatic and non-enzymatic browning. The qRT-PCR reveals that under H₂ fumigation significantly inhibited the expression of phenylpropanoid synthesis pathway-related genes 4CL, CYP73A, HCT01, and REF1, but significantly induce C3'H and HCT02 expression, leading to the change of cinnamic acid, p-coumaric acid, chlorogenic acid and ferulic acid level. In non-enzymatic browning, H₂ fumigate decreased aspartic acid (ASP) level and increased phenylalanine (Phe), tyrosine (Tyr), alanine and glutamic acid (Glu) level by up-regulating the expression levels of amino acid biosynthesis-related genes TYRAAT, ADT, GPT and down-regulating the expression of ASP5 to alleviate browning. H₂ fumigate also induce the expression level of bglX, malQ, SUS and inhibit the expression level of ISA, thus increasing sucrose, glucose, and starch content and decreasing fructose content.

Conclusions

Overall, H₂ could mitigate browning of Lanzhou lily scales by regulating some polyphenol-, amino acid- and sugar-related genes and metabolites.

Graphical abstract

Background

Salinity stress is a critical abiotic factor that significantly impairs crop productivity. Salicylic acid (SA) demonstrates efficacy in mitigating salt stress induced physiological damage across plant tissues. However, the physiological mechanism by which SA alleviates salinity stress in faba bean remains largely unclear. For this purpose, two genotypes of faba bean were subjected to various concentrations of NaCl and SA treatments design.

Results

Salt stress significantly reduced faba bean seedling growth, root architecture, biomass accumulation, and chlorophyll content, ultimately impairing photosynthetic efficiency and reducing yield compared to control plants. However, under 150 mmol L⁻¹ NaCl treatment, chlorophyll a/b ratios, intercellular CO₂ concentration (C_i), non-photochemical quenching (NPQ) of photosystem II (PSII), soluble protein (SP) content, soluble sugar (SS) content, and Na⁺ accumulation in both leaves and roots were markedly elevated compared to controls. The light utilization efficiency of PSII (Fv/Fm, ΦPSII, qP), gas exchange parameters (P_n, G_s, T_r) and contents of SP and SS content increased under the 1.0 mmol L⁻¹ SA + NaCl treatment when compared to the NaCl treatment alone. SA also significantly inhibited Na⁺ uptake and enhanced the absorption of K⁺, Mg²⁺, Ca²⁺, and increased the K⁺/Na⁺ ratio in both roots and leaves of faba bean plants by up-regulating the expression of VfNHX1, VfSOS1, and VfHKT1 under NaCl stress. Moreover, exogenous SA also enhanced the 100-grain weight and pod-setting ability in salt-exposed faba bean plant.

Conclusion

Exogenous SA improved the tolerance of faba bean plants to salinity stress by enhancing PSII light utilization efficiency, osmotic adjustment, root system architecture, and maintaining Na⁺/K⁺ homeostasis.

Graphical Abstract

Background

Soil contamination with metal(loid)s and organic pollutants creates environmental and health concerns, driving the need for sustainable remediation strategies. Organic amendments can mitigate contamination effects, enhancing soil quality, and potentially increasing biomass production; however, their long-term influence remains an open question. In a five-year field experiment at a former wood-preservation site, this study evaluates the effects of five organic amendments—fresh pig manure (PM), biodigested pig manure (PD), compost (C), compost pellets (Pt), and green waste compost (G)—on Cu-contaminated soils. Here, we evaluated their impacts on physico-chemical soil properties, metal bioavailability, microbial community structure, plant growth and soil fertility.

Results

All amendments led to an overall soil improvement, including enhanced physico-chemical properties, increased enzyme activities. The amendments promoted the concentration of soil 16S bacterial genes and improved the yield of winter barley cultivated in the plots. The most abundant phyla detected across soil samples were Actinobacteriota, Proteobacteria, and Firmicutes, with Bacillus, Streptomyces, and Bradyrhizobium among the dominant genera. Compost-based amendments at 5% w/w addition rate (C5 and Pt5) showed the most promising results, significantly increasing soil carbon, nitrogen, and phosphorus contents, while reducing bioavailability of Cd, Ni, Pb, and Zn compared with untreated control plots (p < 0.01). A decrease in Cu availability was observed but it was not significant. The Pt5 soils exhibited the highest 16S rRNA gene copy number (p < 0.01). Both compost and compost pellets amendments enriched microbial communities associated with soil quality and plant yield, leading to significant improvements in soil fertility and barley yield (+ 200% on average).

Conclusion

This integrative approach identified organic amendments, notably compost and pelleted compost, that effectively contribute to soil remediation from multiple perspectives: chemical properties (pH, organic content, nutrients), reduction of bioavailable soil Cd and Zn, enzyme activities, microbial abundance and diversity (16S rRNA), and winter barley yield. The study evidenced signature biomarkers characteristic of healthy soils (Paenibacillus, Lysinibacillus, and Agromyces) and polluted soils (Candidatus Solibacter and Mycobacterium). Our findings support the use of compost (raw and pelleted) as a balanced approach for phyto-managing metal-contaminated soils, reducing 1 M NH₄NO₃-extractable soil Cd and Zn while enhancing microbial activity and soil fertility.

Graphical Abstract

Background

Heartwood accumulates a diverse range of secondary metabolites contributing to its mechanical strength, characteristic coloration, and long-term durability. Toona sinensis is prized for its heartwood, known for its visually unique reddish-brown hue. Despite this, there is a lack of comprehensive metabolomic investigations in the heartwood of T. sinensis.

Results

Here, widely targeted metabolomics was employed to analyze the metabolites of T. sinensis and explore the variances in metabolites of xylems aged between 2 and 6 years. A total of 772 metabolites were identified, including 102 flavonoids, 100 amino acids and their derivatives, and 147 phenolic acids, and others. The 6-year-old heartwood (6YH) exhibited a distinct secondary metabolite profile. Pathway enrichment analysis revealed increased activity in flavone and flavonol biosynthesis as well as flavonoid biosynthesis pathways in 6YH samples. This aligns with the significantly higher accumulation of flavonoids and anthocyanins in this tissue. Heartwood, on the other hand, contains a notable quantity of flavonoid functional groups. In 6YH, the levels of catechin, epicatechin, and cyanidin were higher, whereas in 6-year-old sapwood (6YS), their concentrations were lower. The concentration of epicatechin and catechin in 6YH was measured at 9684 μg/g and 2482 μg/g, respectively. The flavonoids primarily localized around the xylem vessels, with higher concentrations in the earlywood compared to the latewood.

Conclusions

The 6-year-old heartwood of T. sinensis exhibits a unique metabolite profile when compared to other tissues, characterized by a significant accumulation of flavonoids. Most of the flavonoids were localized around the xylem vessels. These findings lay the groundwork for further investigations into the bioactive properties of extracts from T. sinensis heartwood and offer insights that may inform their potential practical applications.

Graphic abstract

Image processing is used for identifying and diagnosing rice leaf diseases in the field of agricultural information. However, in the paddy leaf, identifying fungal infections like powdery mildew, and viral infections are complex. Hence, a novel, “Median Interacted Pigeon Optimization-based Hyperparameter Tuning of CNN for Paddy Leaf Disease Prediction”, has been proposed, in which the existing works focus on size, shape, and texture for leaf disease identification, overlooking fungal disease (powdery mildew) branching patterns and making segmentation more challenging. Thus, a novel Coherent Point Graph Recurrent Network (CPGRN) is introduced, which captures structural branching patterns and recurrent neural networks for temporal coherence, enabling precise segmentation of fungal hyphae. Furthermore, to extract relevant features from images of rice leaf diseases, Convolutional Neural Networks (CNNs) require efficient hyperparameter tuning. Thus, a novel Median Interacted Pigeon-Inspired Optimization (MIPIO) is proposed, which optimizes CNN hyperparameters to enhance the accuracy of characterizing fungal infections and enable the recognition of antagonist interactions among virus species. Moreover, the existing virus identification techniques struggle with antagonistic interactions. To address the unpredictable synergistic effects of multiple viruses co-infecting rice plants and detect co-infections of various viruses, a novel Dynamic Bayesian Adaptive Aesthetic Learning (DBAAL) is proposed, which highly assists in improving the prediction of viral infections in paddy leaves. The experimental results confirm that the proposed approach enhances prediction accuracy, also helps in efficient identification of co-infections of different viruses in rice plants.

Graphical Abstract

Polygonatum cyrtonema Hua functions as a highly valued medicinal herb. However, the seeds of P. cyrtonema exhibit morphophysiological dormancy. In this study, P. cyrtonema seeds were treated with a range of fluridone concentrations (0, 50, 100, 250 and 500 mg/L). The germination rate and radicle length were recorded on the 25th, 30th, 40th, 50th, and 60th days of the experiment. In addition, we investigated the metabolome and transcriptome differences in P. cyrtonema seed under fluridone treatments of 0 mg/L (CK), 50 mg/L (FL5), and 250 mg/L (FL20). The findings revealed that suitable fluridone significantly increased the germination rate and promoted radicle elongation of P. cyrtonema seeds. Furthermore, fluridone treatments significantly promoted the germination by reducing abscisic acid (ABA) content, while increasing the levels of auxin (IAA) and cytokinin (CTK). Most genes associated with IAA and CTK in FL5 and FL20 showed higher expression levels when compared with the control, whereas genes related to dormancy and senescence showed the opposite trend. Moreover, genes associated with phenylpropanoid biosynthesis exhibited significant upregulation in FL5 and FL20 when compared with the control, suggesting that fluridone might alleviate the abiotic stress and provide a more favorable environment for germination. In addition, genes associated with the starch and sucrose metabolism showed significant upregulation, contributing to the energy supply for the seed germination. In summary, this study identified 250 mg/L as the optimal fluridone concentration for promoting the germination of P. cyrtonema seed by regulating hormone-mediated signaling, starch/sucrose metabolism, and phenylpropanoid biosynthesis. The current research provides a theoretical basis and practical techniques for applying fluridone to release the dormancy and enhance germination of P. cyrtonema seeds.

Graphical abstract

Background

Urea-based fertilizers are essential for agricultural productivity but contribute to environmental degradation by releasing soil nitrogen (N) through N leaching and runoff. To address these issues, this study develops and characterizes slow-release composites of thermoplastic starch (TPS) and epoxidized natural rubber (ENR) that incorporate 46-0-0 fertilizer. TPS, recognized for its moisture sensitivity and biodegradability, was blended with ENR to enhance matrix compatibility and optimize nutrient release from the fertilizer. The blending process included different fertilizer concentrations (6.9, 10, 15, and 20 wt%) within various components of the composite.

Results

The characterization included evaluation of mechanical properties, water absorbance, biodegradability in soil, ammonium release, and ammonium leaching. The TPS/ENR composites exhibited a two-stage decomposition, with TPS dissolving first to provide an initial nutrient boost, followed by the biodegradation of ENR to ensure sustained nutrient delivery. Ammonium release assays demonstrated that TPS/ENR composites delayed nutrient dissolution compared to conventional fertilizers, significantly reducing nitrogen loss through leaching. Notably, the TPS/ENR composite with 6.9 wt% of 46-0-0 fertilizer exhibited the highest efficiency, achieving sustained ammonium release and enhancing soil nitrogen retention while mitigating phytotoxicity in lettuce and maize germination assays.

Conclusions

These findings highlight the potential and environmental benefits of delivering fertilizer in TPS/ENR composites to improve nitrogen fertilizer efficiency in agricultural systems. The slow-release mechanism provides both initial and sustained nutrient supply, addressing the dual challenges of early crop nutritional needs and long-term environmental sustainability.

Graphical abstract