ACS agricultural science & technology最新文献

Poly-γ-L-diaminobutanoic acid (γ-PAB) is an antibiotic produced by marine bacteria Bacillus pumilus, showing considerable potential for applications in the fields of food, agriculture, and animal husbandry. The γ-PAB synthetase (Pas) and the γ-PAB-degrading enzyme (Pad) coexist within the cell. To enhance the γ-PAB fermentation production, this study utilized homologous recombination to delete the pad gene of Pad, creating a mutant strain Δpad. The validation of fermentation, achieved through pH adjustments, produced the following findings: (1) γ-PAB yield of Δpad significantly decreased to only 11.2% of that of the parent strain B. pumilus GS3-M7, instead of increasing; (2) by adjusting the pH to 5.5, GS3-M7 completely degraded the accumulated γ-PAB within 6 h, while the γ-PAB concentration in Δpad strain’s culture medium remained unchanged. This indicates the presence of only one type of Pad in B. pumilus and that the Δpad strain lost its degrading activity; (3) analysis of intracellular products and key enzyme activities revealed that the physiological metabolism of Δpad strain was suppressed under γ-PAB stress, and oxidative damage was notably higher compared to GS3-M7; (4) transcriptomic analysis identified 1726 differentially expressed genes (DEGs), in which genes related to oxidation–reduction processes, cationic antimicrobial peptide resistance, and peptidoglycan biosynthesis were significantly upregulated, whereas genes associated with ribosome, macromolecule biosynthesis, TCA cycle, and biosynthesis of various antibiotics were significantly downregulated. These findings demonstrate that Pad in B. pumilus functions as a self-resistance mechanism by degrading intracellular excess γ-PAB, thereby preventing autoinhibition by its own antimicrobial product. This represents a novel subclass of chemical modification mechanisms.

Foliar nutrition and disease management are key agronomic practices in plant cultivation. Tank mix, combining fertilizers and fungicides into a single application, has gained popularity for streamlining field operations. In this work, the compatibility of fertilizers containing Mn and Zn from sulfate and EDTA sources with fungicides of type suspension concentrate and emulsifiable concentrate in the tank mix was evaluated. The pH and electrical conductivity were monitored in all mixtures. Results showed that 27% Mn, 22% Zn, and 70% active fungicides were found in the precipitate. FTIR and UV–vis analyses did not present bandwidth deviations, indicating complexation. Therefore, adsorption was identified as the primary interaction mechanism rather than complexation. In conclusion, pH and electrical conductivity are key indicators of interactions within the tank mix, and the adsorption interaction between fertilizers and fungicides led to a decrease in the availability of components.

2,5-Diketopiperazines (2,5-DKPs), naturally occurring in food and beverages, have demonstrated notable antimicrobial properties. However, their synergism with other secondary metabolites in real food matrices remains largely unexplored. In our study, a group of microbially produced 2,5-DKPs, including proline-based dilactams (Pro-DKPs), was synthesized and evaluated for their efficacy against common foodborne pathogens: Staphylococcus aureus CCM 4516, Escherichia coli CCM 4517, Pseudomonas aeruginosa CCM 1961, Penicillium chrysogenum DBM 4062, Aspergillus niger CCM 8189, and Fusarium culmorum DMF 0109. We also investigated the impact of the polarity of 2,5-DKPs on their antimicrobial effect. Among the four synthesized 2,5-DKPs, cyclo(l-Leu-l-Pro) (Pro-DKP-1) inhibited the growth of F. culmorum DMF 0109 by up to 83%, as determined using the poisoned plate method. Further experiments investigated the synergistic effects of Pro-DKPs in combination with lactic acid at food-relevant concentrations. The addition of lactic acid considerably enhanced the antimicrobial activity of all three Pro-DKPs, with inhibitions reaching up to 99% against F. culmorum DMF 0109. Our findings suggest that employing commercial starter cultures capable of producing 2,5-DKPs, including Pro-DKPs, may offer a promising strategy for extending the shelf life of food products and beverages.

The multibillion-dollar worldwide market for coated seeds is currently seeking new sustainable solutions that promote the use of natural (biobased) polymers for developing seed coating materials produced using clean methodologies. Seed coating is an effective method widely applied in modern agriculture. By uniformly depositing a variety of active ingredients on the seed surface, it is possible to obtain coated seeds with enhanced resistance, germination, and facilitated sowing. Moreover, seed coating is an attractive option for improving crop yield, resistance to biotic and abiotic factors, and restoring degraded soil systems. Petroleum-derived polymers are commercially used in seed coating, which can negatively affect plants, soil, and pollinating animals. Biopolymer seed coatings offer various advantages for reducing environmental contamination, enhancing seed protection, and enabling the addition of beneficial microbial species that promote plant growth. Such seed coatings also improve seed germination, nutrient delivery, and sowing efficiency, while reducing reliance on chemical inputs and contributing to environmentally responsible agriculture. This review highlights the growing importance of biopolymers in seed coating and summarizes their multifaceted use in sustainable agricultural systems.

Climate change-induced diverse abiotic stresses threaten agricultural production. To address this challenge, enhancing a crop’s resilience against diverse abiotic stresses has become imperative. Here, we demonstrate that silver nanoparticles (AgNPs) with reactive oxygen species (ROS)-generating properties can serve as a seed priming agent to simultaneously enhance tolerance of Chinese cabbage (Brassica campestris L.) to diverse abiotic stresses. AgNPs priming (40 mg/L, 4 h) significantly increased ROS levels in Chinese cabbage seeds compared to hydropriming, while enhancing seed germination and seedling growth under drought (5–15% PEG-6000), salinity (50–150 mmol/L NaCl), and low-temperature (10–15 °C) stress conditions. AgNP-primed seeds exhibited significant increases in the vigor index (32.3–85.4%), shoot length (0.16–40.4%), root length (48.5–112.7%), and biomass (6.7–19.7%) relative to hydroprimed seeds. RNA sequencing analysis revealed that AgNPs priming triggered comprehensive transcriptomic reprogramming in the primed seeds. A number of signaling and defense pathways, including plant–pathogen interaction networks, MAPK-mediated stress transduction pathways, phytohormone signaling cascades, glutathione-mediated detoxification systems, and phenylpropanoid biosynthesis, were activated in AgNPs-primed seeds. Notably, this acquired resistance persisted into the vegetative stage. Four-week-old cabbage plants exhibited resistance to drought, cold, and salt. At harvest, the yield of AgNPs-primed plants increased by 10.7–19.3% compared to hydropriming under all tested adverse conditions. These results demonstrate that AgNPs seed priming approach enhances cabbage tolerance to diverse abiotic stresses without yield penalty, offering a simple strategy for cultivating climate-resilient crops.

In semiarid regions, water salinity is one of the main factors limiting the growth, yield and quality of leafy vegetables such as kale. In order to reduce the negative effects of salts on plants, studies have been carried out using growth regulators, such as salicylic acid, which is a promising strategy under stress conditions. The aim of this study was to evaluate the effect of salicylic acid on the growth and quality of kale cv. Tatsoi Shanghai under salt stress in semihydroponic cultivation. The treatments were distributed in a completely randomized design, in a 4 × 3 factorial scheme, referring to four salinity solutions (0.5, 1.5, 2.5, and 3.5 dS m^–1) and three concentrations of salicylic acid (0, 1, and 2 mM) applied via foliar. The variables analyzed were growth, biomass, indices chlorophylls and postharvest quality. The results showed that the application of 1 mM SA under moderate salinity (1.5 dS m^–1) resulted in greater plant height, number of leaves and chlorophyll indices. However, the application of 2 mM SA at high salinity (3.5 dS m^–1) reduced the total dry mass by 24.97% and the Hue angle by 10.14%, affecting visual quality. Without the application of SA, at high salinity, there was an increase of 17.57% in total dry biomass and 28.87% in leaf area, but with a reduction in the intensity of the green color. Based on the results, it was concluded that the effectiveness of SA depends on the concentration used and the level of salinity, with a concentration of 1 mM being the most suitable for mitigating the effects of moderate salt stress on kale cv. Tatsoi Shanghai.

Background: Allylsulfides (All-S) are the bioactive components of garlic essential oil; however, among them, allyl trisulfides (All-S₃) and allyl tetrasulfides (All-S₄) are the most active components present in low concentrations in the essential oil. Herein, these analogs were prepared under laboratory conditions to yield garlic essential oil (L-GEO). L-GEO was synthesized with facile methodology and significant yield with higher relative percentages of All-S₃ and All-S₄. Results: The GC-MS data revealed diallyl trisulfide, diallyl tetrasulfide, and diallyl disulfide in a relative percentage ratio of 37.8%, 36.32%, and 12.65%, respectively, in crude L-GEO. The L-GEO was infused on natural cellulose strips for the efficient release of bioactive components as fumigants against Callosobruchus maculatus (F.) in stored green grams. Appreciable toxicity was revealed by the L-GEO with LC₅₀ (24 h) and LC₉₉ (24 h) values of 28.5 and 82.6 μL/L, respectively. No F₁ progeny emergence was observed at optimized LC₉₉ (24 h) dose. Additionally, varying levels of changes were observed in enzymatic activities, viz. acetylcholinesterase, catalase, and superoxide dismutase, in the bodies of treated insects, presenting the modulation of enzymatic activity responsible for insect mortality. Conclusion: L-GEO was presented as an efficient and eco-friendly material to manage pulse beetle C. maculatus in green grams under storage conditions.

Gladiolus, a significant ornamental crop in global floriculture, frequently suffers substantial economic damage due to persistent Fusarium infections despite widespread fungicide applications. The present study systematically evaluated Fusarium diversity, pathogenicity, and fungicide resistance associated with Gladiolus crops, demonstrating the complexity in Fusarium pathogenesis. Initially, 730 Fusarium-like isolates were obtained from infected Gladiolus tissues and subsequently narrowed down to 30 isolates based on in vitro pathogenicity assays and fungicide resistance screening against carbendazim. Further selection identified 10 highly virulent isolates demonstrating resistance to carbendazim, propiconazole, and copper oxychloride. Molecular characterization using ITS and Tef1 gene sequencing classified the isolates into species complexes (SC) of Fusarium oxysporum (FOSC), Fusarium fujikuroi (FFSC), and Fusarium solani (FSSC). Isolates from the FFSC exhibited pronounced pathogenicity, with isolate GKF-6 (Fusarium circinatum) identified as the most aggressive pathogen for Gladiolus. Controlled pathogenicity assessments revealed rapid and extensive disease spread following aerial inoculation of spores, indicating that Fusarium dispersal is not limited to soil-borne mechanisms. Moreover, disease symptoms on Gladiolus plants differed with the mode and time of infection. These critical observations, along with the demonstrated fungicide resistance and genetic diversity of Fusarium isolates, highlight the necessity of revisiting current disease management strategies heavily reliant on fungicides.

Urea-formaldehyde (UF), a prominent slow-release nitrogen fertilizer, faces challenges in production optimization to efficiently meet the varying slow-release needs of different crops. This study employed response surface methodology (RSM) analysis combined with an artificial neural network-genetic algorithm (ANN-GA) prediction to refine the UF polymerization process. Key factors influencing the polymerization process and the slow-release properties of UF products were identified as the urea/formaldehyde molar ratio (U/F) and reaction pH. The ANN-GA model demonstrated superior prediction accuracy over the RSM model, achieving coefficient of determination (R²) values of 0.9968 for cold water-insoluble substances (CWI) and 0.9979 for hot water-insoluble substances (HWI), representing improvements of 0.6% and 0.43%, respectively. By utilizing a fitness function that incorporated the UF activity index as the objective, the model optimized process parameter combinations, yielding relative errors below 4% between predicted and experimental values. The ANN-GA model facilitated precise control over UF polymerization, enabling the synthesis of short-cycle slow-release UF derived from methylenediurea (MDU) for rapid nutrient delivery and long-cycle UF based on trimethylenetraurea (TMTU) for sustained nutrient release. This study introduces a novel framework for regulating fertilizer manufacturing processes in precision agriculture, employing a “demand-driven → algorithmic optimization → targeted synthesis” approach that provides quick and adaptive solutions.

This study evaluates the nematicidal potential of white mustard seeds (Sinapis alba (S. alba), family Brassicaceae) in vitro and as a biofumigant against root-knot nematodes, Meloidogyne spp., infecting tomato plants under field conditions. In vitro assays revealed that S. alba extract has effectively inhibited Meloidogyne incognita egg hatching after 4 days with 94% and increased the mortality rates of juveniles by 77 and 90% after 24 and 48 h. respectively. In field experiments, three doses of mustard seeds were applied, results showed a significant reduction in nematode populations, including galls, egg masses, and second-stage juveniles, as the treatment doses increased. In addition to nematode suppression, plant growth parameters, such as shoot and root length and fruit weight, were significantly enhanced with higher doses of white mustard seed treatment. The treatments also improved the defense mechanisms of the tomato plants, elevating antioxidant levels, antioxidant enzyme activities, and the content of flavonoids and phenolic compounds. Chemical profiling of the white mustard seeds by LC-HRESI-MS/MS revealed the presence of various compounds, mainly phenolic acids and their derivatives and flavonoids, which may contribute to the observed nematicidal effects.