Search

Nitrate (NO3–) and ammonium (NH4+) are two main inorganic nitrogen (N) sources during crop growth. Here, we enhanced the expression of OsAMT1.1, which encodes a NH4+ transporter, using the NO3–-inducible promoter of OsNAR2.1 and an ubiquitin promoter in transgenic rice plants. Under field condition of 120 kg /hm2 N, agronomic N use efficiency, N recovery efficiency and N transport efficiency, and grain yield of the pOsNAR2.1:OsAMT1.1 transgenic lines were increased compared with those of the wild type (WT) and the pUbi:OsAMT1.1 transgenic plants. Under 2.0 mmol/L NO3– + 0.5 mmol/L NH4+ and 0.5 mmol/L NO3– + 2.0 mmol/L NH4+ conditions of hydroponic culture, compared with the WT, both biomass and total N content were increased in the pOsNAR2.1:OsAMT1.1 transgenic lines. However, biomass was significantly reduced in pUbi:OsAMT1.1 transgenic plants under 0.5 mmol/L NO3– + 2.0 mmol/L NH4+ condition. The lines expressing pOsNAR2.1:OsAMT1.1 exhibited increased OsAMT1.1 expression and 15NH4+ influx in roots under both 2.0 mmol/L NO3– + 0.5 mmol/L NH4+ and 0.5 mmol/L NO3– + 2.0 mmol/L NH4+ conditions. Our study showed that expression of OsAMT1.1 can be promoted when driven by the OsNAR2.1 promoter, especially under high-level nitrate condition, leading to enhancement of NH4+ uptake, N use efficiency and grain yield.

Sonic layer depth (SLD) is crucial in ocean acoustics research and profoundly influences sound propagation and Sonar detection. Carrying 90% of oceanic kinetic energy, mesoscale eddies significantly impact the propagation of acoustic energy in the ocean. Recent studies classified mesoscale eddies into normal eddies (warm anticyclonic and cold cyclonic eddies) and abnormal eddies (cold anticyclonic and warm cyclonic eddies). However, the influence of mesoscale eddies, especially abnormal eddies, on SLD remains unclear. Based on satellite altimeter and reanalysis data, we explored the influence of mesoscale eddies on seasonal variations in SLD in the South China Sea. We found that the vertical structures of temperature anomalies within the eddies had a significant impact on the sound speed field. A positive correlation between sonic layer depth anomaly (SLDA) and eddy intensity (absolute value of relative vorticity) was investigated. The SLDA showed significant seasonal variations: during summer (winter), the proportion of negative (positive) SLDA increased. Normal eddies (abnormal eddies) had a more pronounced effect during summer and autumn (spring and winter). Based on mixed-layer heat budget analysis, it was found that the seasonal variation in SLD was primarily induced by air–sea heat fluxes. However, for abnormal eddies, the horizontal advection and vertical convective terms modulated the variations in the SLDA. This study provides additional theoretical support for mesoscale eddy–acoustic coupling models and advances our understanding of the impact of mesoscale eddies on sound propagation. [ABSTRACT FROM AUTHOR]

The substitution of natural gas hydrates with CO2 offers a compelling dual advantage by enabling the extracting of CH4 while simultaneously sequestering CO2. This process, however, is intricately tied to the mechanical stability of CO2-CH4 heterohydrates. In this study, we report the mechanical properties and cage transformations in CO2-CH4 heterohydrates subjected to uniaxial straining via molecular dynamics (MD) simulations and machine learning (ML). Results indicate that guest molecule occupancy, the ratio of CO2 to CH4 and their spatial arrangements within heterohydrate structure greatly dictate the mechanical properties of CO2–CH4 heterohydrates including Young's modulus, tensile strength, and critical strain. Notable, the introduction of CO2 within clathrate cages, particularly within 512 small cages, weakens the stability of CO2–CH4 heterohydrates in terms of mechanical properties. Upon critical strains, unconventional clathrate cages form, contributing to loading stress oscillation before fracture of heterohydrates. Intriguingly, predominant cage transformations, such as 51262–4151063 or 425864 and 512–425861 cages, are identified, in which 4151062 appears as primary intermediate cage that is able to transform into 4151063, 425862, 425863, 512 and 51262 cages, unveiling the dynamic nature of heterohydrate structures under straining. Additionally, ML models developed using MD data well predict the mechanical properties of heterohydrates, and underscore the critical influence of the spatial arrangement of guest molecules on the mechanical properties. These newly-developed ML models serve as valuable tools for accurately predicting the mechanical properties of heterohydrates. This study provides fresh insights into the mechanical properties and cage transformations in heterohydrates in response to strain, holding significant implications for environmentally sustainable utilization of CO2–CH4 heterohydrates. [ABSTRACT FROM AUTHOR]

With the continuous research on functional factors, the essential components in functional foods, numerous functional factors have been developed and applied to functional foods. For instance, unsaturated fatty acids, polyphenols and carotenoids have their own low bioavailability due to their special physicochemical properties, thus restricting their application in food. Therefore, the development of functional factor transport systems to improve the utilization of functional factors in food organisms has become an urgent problem to be solved. In this paper, we systematically summarize the physicochemical properties of nanoemulsions, multilayer emulsions, solid -phase lipid particles, and gel particles based on recent research on functional factor delivery systems and explain the mechanism of action and application of various delivery systems. The target delivery system could help improve functional factors' problems and achieve the controlled release of targeted action sites in vivo. Conclusively, this paper aims to lay a theoretical basis for developing and applying targeted delivery systems for functional factors in the food industry. [ABSTRACT FROM AUTHOR]

Gray mold caused by the necrotrophic fungal pathogen Botrytis cinerea is one of the most destructive diseases in rose (Rosa spp.). Rose infection by B. cinerea leads to severe economic losses due to necrosis, tissue collapse, and rot. In rose, cytokinins (CKs) positively regulate a defense response to B. cinerea , but little is known about the underlying molecular mechanisms. Here, we characterized two ethylene/jasmonic acid-regulated transcription factors, RhEFR005 and RhCCCH12, that bind to the promoter region of PATHOGENESIS-RELATED 10.1 (RhPR10.1) and promote its transcription, leading to decreased susceptibility to B. cinerea. The RhEFR005/RhCCCH12–RhPR10.1 module regulated cytokinin content in rose, and the susceptibility of RhEFR005 -, RhCCCH12 -, and RhPR10.1 -silenced rose petals can be rescued by exogenous CK. In summary, our results reveal that the RhERF005/RhCCCH12–RhPR10.1 module regulates the CK-induced defense response of rose to B. cinerea. [ABSTRACT FROM AUTHOR]