Response of lignin and flavonoid metabolic pathways in Capsicum annuum to drought and waterlogging stresses

Water stress is a critical factor limiting the growth and development of Capsicum annuum. Flavonoids and lignin are important secondary metabolites that serve as signaling molecules in plant stress responses. However, the effects and regulatory mechanisms of lignin and flavonoids under water stress in Capsicum annuum remain unknown. The present study focused on the effects of drought and waterlogging stress on the morphology, hydrogen peroxide, and relative chlorophyll (SPAD), as well as enzyme activities, metabolite contents, and gene expression related to lignin and flavonoid metabolic pathways in Capsicum annuum. The results showed that drought and waterlogging stresses on the Capsicum annuum variety ‘Shuyu2’ significantly reduced plant height, stem thickness, and single-fruit weight, and increased fruit shape coefficients. Drought stress increased H2O2 and SPAD content, enhanced the activity levels of metabolic enzymes (phenylalanine deaminase, cinnamate 4-hydroxylase, coenzyme A ligase, peroxidase, and polyphenol oxidase), and up-regulated the expression of related genes, phenylalanine deaminase (PAL), trans-cinnamate monooxygenase (C4H), chalcone isomerase (CHI), and mangiferyl hydroxycinnamoyltransferase (HCT), while also promoting the accumulation of metabolites (total phenolics, flavonoids, and lignin) that have a restorative effect on drought stress. The continuous accumulation of H2O2 and the increase and then decrease in SPAD under waterlogging stress was also observed. Waterlogging stress also enhanced the activities of the above-mentioned metabolic enzymes, but the related genes were selectively down-regulated, e.g., C4H, 4CL, and peroxidase (POD), which resulted in the inhibition of the synthesis of lignin, flavonoids, and total phenols. These results indicate that the Capsicum annuum variety ‘Shuyu2’ is a drought-tolerant, waterlogging-sensitive variety. Meanwhile, the lignin and flavonoid pathway is a key pathway in response to drought stress in Capsicum annuum, which improves the theory of stress tolerance breeding in Capsicum annuum

Disentangling the Drivers of Diversity and Distribution of Fungal Community Composition in Wastewater Treatment Plants Across Spatial Scales

Activated sludge microbial community composition is a key bio-indicator of the sustainability of wastewater treatment systems. Therefore, a thorough understanding of the activated sludge microbial community dynamics is critical for environmental engineers to effectively manage the wastewater treatment plants (WWTPs). However, fungal communities associated with activated sludge have been poorly elucidated. Here, the activated sludge fungal community in 18 geographically distributed WWTPs was determined by using Illumina sequencing. The results showed that differences in activated sludge fungal community composition were observed among all WWTPs and also between oxidation ditch and anaerobic-anoxic-aerobic (A/A/O) systems. Ascomycota was the largest phyla, followed by Basidiomycota in all samples. Sporidiobolales and Pezizales were the most abundant order in oxidation ditch and A/A/O systems, respectively. The network analysis indicated cooperative and co-occurrence interactions between fungal taxa in order to accomplish the wastewater treatment process. Hygrocybe sp., Sporobolomyces sp., Rhodotorula sp., Stemphylium sp., Parascedosporium sp., and Cylindrocarpon sp., were found to have statistically significant interactions. Redundancy analysis revealed that temperature, total phosphorus, pH, and ammonia nitrogen were significantly affected the fungal community. This study sheds light on providing the ecological characteristics of activated sludge fungal communities and useful guidance for improving wastewater treatment performance efficiency

Experimental study of gas composition in the equilibrium state of a light alkane combustion reaction

Oil field-associated gas is typically a mixture of light alkanes. To ensure production safety, it is essential to investigate the combustion characteristics and the reaction mechanism of light alkane gas mixtures to uncover the underlying mechanisms of the combustion reaction. This paper investigates the equilibrium gas component concentrations resulting from the reaction of a gas mixture of methane, ethane, and propane at specific ratios through experimental tests. The study's results demonstrate that the equilibrium concentrations of methane, ethane, and propane initially decrease and then increase with the rise of the equivalence ratio under the same initial pressure conditions. In oxygen-poor conditions, the equilibrium concentration ratio of methane gradually increases in proportion to the equilibrium ratio, confirming that ethane and propane are the preferred participants in the reaction. Furthermore, a study of the equilibrium concentration of the critical intermediate product, ethylene, revealed that it does not completely oxidize in the combustion reaction. It can persist under both oxygen-rich and oxygen-poor conditions, with an equilibrium concentration of approximately 0.02%. The findings of this paper can serve as a theoretical supplement to the research on explosive gas combustion and explosions

Robust fault recovery strategy for multi-source flexibly interconnected distribution networks in extreme disaster scenarios

To enhance the resilience of power distribution networks against extreme natural disasters, this article introduces a robust fault recovery strategy for multi-source, flexible interconnected power distribution networks, particularly under scenarios of extreme disasters. Initially, the comprehensive risk of system failure due to ice load on distribution lines and poles is fully considered, and a model for the overall failure rate of lines is constructed. This model addresses the diverse failure scenarios triggered by various meteorological conditions. Through the use of information entropy, typical extreme disaster failure scenarios are identified, and lines with high failure rates under these scenarios are determined. Subsequently, a box-type interval model is developed to represent the uncertainty in the output of distributed generation (DG), and on this basis, a robust fault recovery model for multi-source power distribution networks interconnected through soft open points (SOPs) is established, and use the Column and Constraint Generation (C&CG) algorithm to solve the problem. Finally, the fault recovery model and strategy proposed are validated through an illustrative example based on a modified IEEE 33-node interconnected system

A Review on the Functional Properties, Extraction and Microencapsulation of Almond Oil

Almond oil is a kind of functional edible oil with rich nutrition and high medicinal value. This paper reviews the various functional properties of almond oil such as antioxidation, hypoglycemic effect and cardiovascular disease prevention, as well as the extraction and microencapsulation technology at home and abroad. The benefits and drawbacks of all these technical methods are made clear by comparing various extraction techniques, such as mechanical expression, solvent extraction, and water extraction of almond oil, as well as microencapsulation techniques, such as spray drying, complex coacervation, extrusion, and freeze-drying. The study provides a feasible, quick, effective, and secure technology for the industrial production and preparation of almond oil and might serve as a theoretical reference for its stable preparation and rational utilization

Influence of punch radius on elastic modulus of three-point bending tests

Three-point bending is one of the most common methods of studying the mechanical performance of materials. The influence of punch radius in the measurements is not considered in the previous studies. This article focuses on the influence of the punch radius on the elastic modulus. The experiment is set up to measure the elastic modulus of 6061 aluminum alloy (6061 Al) and copper as the specimens, in which several different radii of punches are used. The maximum bending deflection of the middle point is 1.0 mm. Moreover, a finite element simulation is constructed to simulate the bending process of specimen, which is consistent with the experimental results. According to the results, the punch radius has affected the measurement of elastic modulus, and the elastic modulus, the contact length, and the peak load increase with the increase in the punch radius. Combining the experiment result ( E 1 ) and the standard result ( E 3 ) of Changchun research institute for testing machines, it is found that the appropriate punch radius is in the range from 2.5 to 3.0 mm for this experiment, when the specimen’s dimension is 30.0 mm × 6.0 mm × 1.0 mm

Variations of mechanical property of out circumferential lamellae in cortical bone along the radial by nanoindentation

Because the out circumferential lamellae have a special protective effect on the cortical bone, it is very important to understand the variations of the mechanical property of the out circumferential lamellae in cortical bone. For the purpose, the elasticity modulus and hardness of out circumferential lamellae in cortical bone were investigated in two orthogonal planes by nanoindentation, and the comparisons were made for both elasticity modulus and hardness between the two orthogonal planes. From the experiments, the decreasing trend was discovered for elasticity modulus from inside to outside in the transverse plane and ruleless variations tendency was presented in the longitudinal plane. The hardness presented the same variations in two orthogonal planes with elasticity modulus in respective plane. In the same layer, the elasticity modulus in the transverse plane was higher than that in the longitudinal plane, and the difference values between them turned to be smaller. In contrast, the hardness in the longitudinal plane was higher than that in the transverse plane in all the layers. From the heterogeneity and the microstructure of the material, the influence factors were discussed. A soft to hard structure model was put forward, and the coordinating protection mechanism of buffer and support was described. Investigation of variations of mechanical properties of out circumferential lamellae in cortical bone can provide some new understanding in researches of fracture of bone, interface load effect and design of bone graft

Exogenous Xyloglucan Oligosaccharides Alleviate Cadmium Toxicity in <i>Boehmeria nivea</i> by Increasing the Cadmium Fixation Capacity of Cell Walls

Xyloglucan is an important component of hemicellulose, and xyloglucan oligosaccharides (Xh), which are metabolized by xyloglucan, play an important role in plant growth and development. However, the regulatory effects of the external application of Xh under cadmium (Cd) stress have not been determined. In this study, we evaluated the mechanism by which Xh contributes to resistance to Cd stress in ramie, a candidate plant species for toxic ion removal. The external application of Xh effectively attenuated the effects of Cd on ramie growth and photosynthetic pigments. Cd stress can also inhibit the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX), resulting in a significant increase in the extent of membrane lipid peroxidation. After the external application of Xh, antioxidant enzyme activity was up-regulated, and damage to membranes in plants was reduced. In addition, the external application of Xh increased Cd retention in roots, thereby significantly decreasing Cd content in shoots. The external application of Xh also regulated the subcellular distribution of Cd and increased the Cd content of the cell wall. In particular, a root cell wall analysis revealed that Cd+Xh treatment significantly increased the hemicellulose content in the cell wall and the amount of Cd retained. In summary, the external application of Xh alleviates Cd toxicity in ramie by increasing the hemicellulose content and the Cd fixation ability of the cell wall and by reducing membrane lipid peroxidation via antioxidant enzymes