ACS agricultural science & technology最新文献

Thousands of tons of two-phase olive mill solid waste (2P-OMSW) are generated annually, necessitating effective valorization strategies. Composting has been widely explored as a management approach; however, the extended processing time required for these residues poses a significant challenge for the olive industry. In this study, a forced aeration system combined with a semipermeable cover was implemented at a demonstrative scale to enhance the composting process and reduce its duration. Additionally, process optimization was evaluated through a two-stage composting strategy. In stage I, compost preconditioning was carried out using two types of manure (poultry and cow). In stage II, a bioaugmentation process was introduced using the edible fungus Pleurotus eryngii. The composting of 2P-OMSW under forced aeration and a semipermeable cover lasted 90 days. During the composting process, physicochemical parameters, total phenol content, microbial analysis, and phytotoxicity bioassays were measured to evaluate the efficiency and quality of the final compost. In stage I, poultry manure proved to be more effective than cow manure, resulting in a lower C/N ratio (<25%), higher nitrogen, phosphorus, and potassium content, and a greater reduction in total phenol content (>70%). In stage II, bioaugmentation significantly enhanced the removal of heavy metals, particularly zinc (Zn) and copper (Cu). Both final composts, obtained within 90 days, exhibited enriched nutrient content, stabilized nonphytotoxic organic matter, and low heavy metal concentrations. The findings highlight the potential of a forced aeration system combined with a semipermeable cover as an effective strategy for composting 2P-OMSW. This approach facilitates the transformation of 2P-OMSW into high-quality compost, making it suitable for use as an organic amendment or fertilizer in agricultural systems. Furthermore, it allows for the management of this residue within a relatively short time frame.

Salinity remains a major obstacle to tomato production; yet, the interplay between ion accumulation and gene expression in conferring salinity tolerance is not fully understood. In this study, the cultivars ‘Sanibel’ and ‘Tasti-Lee’ were subjected to four salinity treatments [1.5 (T0), 4 (T1), 8 (T2), and 12 (T3) dS m^–1] to examine morphological, ionic, and molecular responses. Elevated salinity led to significant declines in shoot and root dry weight, plant height, root length, and leaf number, with the steepest reduction observed at 12 dS m^–1 (T3). Ion profiling revealed increasing Na and Cl concentrations in roots and shoots. However, ‘Tasti-Lee’ appeared to reach its highest Na and Cl accumulation in leaves at 8 dS m^–1. Both cultivars also showed diminished K in leaves and stems; yet root K unexpectedly rebounded at the highest salinity. Gene expression analysis revealed that SOS1, SOS2, and NHX1─key mediators of Na⁺ extrusion and sequestration─were upregulated in the roots of both cultivars, while HKT1 was downregulated, suggesting decreased Na⁺ retrieval under severe stress. In leaves, genes such as SAL1, CLCg, NPF2.4, and NPF2.5 were downregulated, likely limiting the additional ion influx into photosynthetically active tissues. Variety-specific regulation also emerged. In ‘Sanibel’, NHX2 and CCC were upregulated in roots, indicating reliance on vacuolar Na⁺ compartmentalization and enhanced Cl^– regulation, while ‘Tasti-Lee’ downregulated NPF2.4, suggesting a different route for restricting Cl^– movement. In leaves, AKT1 and HSP90.7 were induced under T3 in ‘Tasti-Lee’ but not in ‘Sanibel’, whereas CCC and CLCc were upregulated in ‘Sanibel’ only. These different mechanisms of controlling Na⁺ and Cl^– underscore both shared and cultivar-specific salinity-tolerance strategies, providing crucial insights for developing salt-tolerant tomato lines.

Climacteric fruits like banana undergo rapid ripening, characterized by a burst in respiration and ethylene production, which negatively impacts their quality and storage life and hastens the spread of postharvest diseases such as anthracnose. The postharvest application of environmentally sustainable biomolecules such as melatonin and salicylic acid could modulate ripening-related enzyme activity and strengthen disease resistance, thereby delaying fruit ripening. Therefore, this study examined the effects of two biomolecules, melatonin (1.0 and 1.5 mM) and salicylic acid (1.0 and 1.5 mM), applied as a 15 min postharvest dip, individually and in combination, on ripening, postharvest quality, shelf life, and disease incidence management in banana cv. Nendran. The postharvest dip of melatonin (1.0 mM) significantly modulated the activity of fruit ripening enzymes like polygalacturonase and pectin methyl esterase by controlling ethylene synthesis and respiration rate. This treatment also maintained the structural integrity of the fruit compared to the conventional treatment under ambient (32 ± 2 °C) and cold storage (14 ± 1 °C) conditions. Interestingly, melatonin reduced anthracnose incidence by maintaining fruit firmness and boosting the antioxidant activity. The melatonin treatment maintained the shelf life of Nendran banana to 12 days in ambient storage and 36 days under cold storage, which are 3 and 5.34 days longer than their respective controls. Though salicylic acid also improved the postharvest quality and shelf life, its performance was comparatively lower than that of melatonin, imparting moderate control over ripening enzymes and effects on disease incidence and shelf life (10.33 and 11 days in ambient storage and 34.67 and 33.67 days in cold storage, respectively, by 1.0 and 1.5 mM salicylic acid dip). These findings suggest that melatonin (1.0 mM) could serve as a promising postharvest treatment for maintaining quality, prolonging shelf life, and managing anthracnose in bananas during storage.

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.