Examining starch metabolism in lotus roots (Nelumbo nucifera Gaertn.) during post-harvest storage at different temperatures.

This study explores the impact of postharvest storage temperatures (4 °C and 25 °C) on starch metabolism and textural attributes of glutinous lotus root. While starch metabolism is a well-known factor influencing texture, changes in powdery and sticky qualities have remained unexplored. Our research reveals that storing lotus roots at 4 °C delays water dissipation, amylopectin reduction, and the decline in textural elements such as hardness, adhesiveness, springiness, gumminess, and resilience. Lower temperatures postpone amylopectin reduction and sugar interconversion, thereby preserving the sticky texture. Additionally, they suppress starch formation, delay starch metabolism, and elevate the expression of genes involved in starch metabolism. The correlation between gene expression and root texture indicates the critical role of gene regulation in enzyme activity during storage. Overall, low-temperature storage extends lotus root preservation by regulating metabolite content, enzyme activities, and the corresponding genes involved in starch metabolism, preserving both intrinsic and external root quality.

Production of biliverdin by biotransformation of exogenous heme using recombinant Pichia pastoris cells.

Biliverdin, a bile pigment hydrolyzed from heme by heme oxygenase (HO), serves multiple functions in the human body, including antioxidant, anti-inflammatory, and immune response inhibitory activities. Biliverdin has great potential as a clinical drug; however, no economic and efficient production method is available currently. Therefore, the production of biliverdin by the biotransformation of exogenous heme using recombinant HO-expressing yeast cells was studied in this research. First, the heme oxygenase-1 gene (HO1) encoding the inducible plastidic isozyme from Arabidopsis thaliana, with the plastid transport peptide sequence removed, was recombined into Pichia pastoris GS115 cells. This resulted in the construction of a recombinant P. pastoris GS115-HO1 strain that expressed active HO1 in the cytoplasm. After that, the concentration of the inducer methanol, the induction culture time, the pH of the medium, and the concentration of sorbitol supplied in the medium were optimized, resulting in a significant improvement in the yield of HO1. Subsequently, the whole cells of GS115-HO1 were employed as catalysts to convert heme chloride (hemin) into biliverdin. The results showed that the yield of biliverdin was 132 mg/L when hemin was added to the culture of GS115-HO1 and incubated for 4 h at 30 °C. The findings of this study have laid a good foundation for future applications of this method for the economical production of biliverdin.

Ethylene induced AcNAC3 and AcNAC4 take part in ethylene synthesis through mediating AcACO1 during kiwifruit (Actinidia chinensis) ripening.

BACKGROUND: Ethylene plays a vital role in the ripening process of kiwifruit. A terrific amount of transcription factors (TFs) have been shown to regulate ethylene synthesis in various fruits. RESULTS: In this research, two new NAC TFs, named AcNAC3 and AcNAC4, were isolated from kiwifruit, which belonged to NAM subfamily. Bioinformatics analysis showed that both AcNAC3 and AcNAC4 were hydrophilic proteins with similar three-dimensional structures. The expression levels of AcNAC3, AcNAC4 and AcACO1 increased during kiwifruit ripening, as well as were induced by ethylene and repressed by 1-methylcyclopropene (1-MCP). Correlation analysis exhibited that ethylene production was positively correlated with the expression levels of AcNAC3, AcNAC4 and AcACO1. Moreover, both AcNAC3 and AcNAC4 acted as transcriptional activators and could bind to and activate AcACO1 promoter. CONCLUSION: All results unveiled that the ethylene-induced AcNAC3 and AcNAC4 were transcriptional activators, and might participate in kiwifruit ripening and ethylene biosynthesis through activating AcACO1, providing a new insight of ethylene synthetic regulation during kiwifruit ripening. © 2024 Society of Chemical Industry.

Two NAC transcription factors regulated fruit softening through activating xyloglucan endotransglucosylase/hydrolase genes during kiwifruit ripening.

Kiwifruit is a climacteric fruit that is prone to ripening and softening. Understanding molecular regulatory mechanism of kiwifruit softening, is helpful to ensure long-term storage of fruit. In the study, two NAC TFs and two XTH genes were isolated from kiwifruit. Phylogenetic tree showed that both AcNAC1 and AcNAC2 belonged to NAP subfamily, AcXTH1 belong to I subfamily, and AcXTH2 belong to III subfamily. Bioinformatics analysis predicted that AcNAC1 and AcNAC2 possessed similar three-dimensional structural, and belonged to hydrophilic proteins. AcXTH1 and AcXTH2 were hydrophilic proteins and contained signal peptides. AcXTH1 had a transmembrane structure, but AcXTH2 did not. qRT-PCR results showed that AcNAC1, AcNAC2, AcXTH1 and AcXTH2 were increased during kiwifruit ripening. Correlation analysis showed that kiwifruit softening was closely related to endotransglucosylase/hydrolase genes and NAC TFs, as well as there was also a close relationship between AcXTHs and AcNACs. Moreover, both AcNAC1 and AcNAC2 were transcriptional activators located in nucleus, which bound to and activated the promoters of AcXTH1 and AcXTH2. In shortly, we proved that the roles of NAC TFs in mediating fruit softening during kiwifruit ripening. Altogether, our results clarified that AcNAC1 and AcNAC2 were transcriptional activators, and took part in kiwifruit ripening and softening through activating endotransglucosylase/hydrolase genes, providing a new insight of fruit softening network in kiwifruit ripening.

Overexpression of the Chrysanthemum lavandulifolium ROS1 gene promotes flowering in Arabidopsis thaliana by reducing the methylation level of CONSTANS.

DNA demethylation is involved in the regulation of flowering in plants, yet the underlying molecular mechanisms remain largely unexplored. The RELEASE OF SILENCING 1 (ROS1) gene, encoding a DNA demethyltransferase, plays key roles in many developmental processes. In this study, the ROS1 gene was isolated from Chrysanthemum lavandulifolium, where it was strongly expressed in the leaves, buds and flowers. Overexpression of the ClROS1 gene caused an early flowering phenotype in Arabidopsis thaliana. RNA-seq analysis of the transgenic plants revealed that differentially expressed genes (DEGs) were significantly enriched in the circadian rhythm pathway and that the positive regulator of flowering, CONSTANS (CO), was up-regulated. Additionally, whole-genome bisulphite sequencing (WGBS), PCR following methylation-dependent digestion with the enzyme McrBC, and bisulfite sequencing PCR (BSP) confirmed that the methylation level of the AtCO promoter was reduced, specifically in CG context. Overall, our results demonstrated that ClROS1 accelerates flowering by reducing the methylation level of the AtCO promoter. These findings clarify the epigenetic mechanism by which ClROS1-mediated DNA demethylation regulates flowering.

Adsorption of tetracycline from aqueous solution by ZIF-8: Isotherms, kinetics and thermodynamics.

In this study, ZIF-8 nanoparticles were synthesized using a simple method at room temperature. The ZIF-8 nanoparticles were then characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), BET (Brunauer-Emmett-Teller) specific surface area, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and zeta potential. Subsequent batch adsorption experiments evaluated the adsorption performance of ZIF-8 on tetracycline, examining key pa-rameters like reaction time, pH, temperature, and adsorbent dosage. The results revealed a removal rate for TC of up to 90.59%. The adsorption data aligned with the Sips model, showcasing a maximum adsorption capacity of 359.61 mg/g at 303K. Further, the adsorption kinetics adhered to the pseudo-second-order kinetic model with an equilibrium adsorption capacity of 90 mg/g at 303K. The considerable specific surface area of ZIF-8, standing at 1674.169 m2/g, likely enhances the adsorption efficacy. Analysis using XRD and FTIR confirmed the adsorption of TC on the ma-terial's surface. Overall, the predominant driving forces behind the adsorption process were identified as electrostatic interactions and π-π stacking interactions.

Unfolding COVID-19 vaccine communication campaigns in China's neighborhoods: a qualitative study of stakeholders' narratives.

Introduction: The Chinese state has recently implemented the COVID-19 Vaccine Communication Campaign (CVCC) to counter vaccine hesitancy. Nonetheless, the extant literature that examines COVID-19 vaccine acceptance has less represented COVID-19 vaccine communication efforts. Methods: To address this lacuna, we qualitatively explored how CVCCs were organized in Chinese communities by investigating 54 Chinese stakeholders. Results: This study indicates that the CVCC was sustained by top-down political pressure. CVCCs' components involve ideological education among politically affiliated health workers, expanding health worker networks, training health workers, implementing media promotion, communicating with residents using persuasive and explanatory techniques, encouraging multistakeholder partnerships, and using public opinion-steered and coercive approaches. While CVCCs significantly enhanced COVID-19 vaccine acceptance, lacking open communication, stigmatizing vaccine refusers, insufficient stakeholder collaboration, and low trust in the COVID-19 vaccination program (CVP) eroded the validity of CVCCs. Discussion: To promote the continuity of CVCCs in China, CVCC performers are expected to conduct open and inclusive communication with residents. Furthermore, CVP planers should create robust partnerships among health workers by ensuring their agreements on strategies for implementing CVCCs and optimize COVID-19 immunization service provision to depoliticize CVPs. Our study will not only deepen global audiences' understanding of CVCCs in authoritarian China but also offer potential neighborhood-level solutions for implementing local and global public health communication efforts.

In toto imaging of glial JNK signaling during larval zebrafish spinal cord regeneration.

Identification of signaling events that contribute to innate spinal cord regeneration in zebrafish can uncover new targets for modulating injury responses of the mammalian central nervous system. Using a chemical screen, we identify JNK signaling as a necessary regulator of glial cell cycling and tissue bridging during spinal cord regeneration in larval zebrafish. With a kinase translocation reporter, we visualize and quantify JNK signaling dynamics at single-cell resolution in glial cell populations in developing larvae and during injury-induced regeneration. Glial JNK signaling is patterned in time and space during development and regeneration, decreasing globally as the tissue matures and increasing in the rostral cord stump upon transection injury. Thus, dynamic and regional regulation of JNK signaling help to direct glial cell behaviors during innate spinal cord regeneration.

Melatonin treatment delays the softening of blueberry fruit by modulating cuticular wax metabolism and reducing cell wall degradation.

The effects of postharvest melatonin (MT) treatment on cuticular wax and cell wall metabolism in blueberry fruit (Vaccinium spp.) were evaluated. The results revealed that MT treatment maintained the cuticular wax rod-like structure and delayed wax degradation. The gas chromatography-mass spectrometry analysis results revealed that MT application changed the cuticular wax composition in blueberries, and 25 metabolic components were screened. The metabolic regulation of wax quality in blueberry fruit may therefore be influenced by MT. Additionally, MT slowed down pectin and cellulose degradation by reducing the activities of cell wall degrading enzymes like pectin methyl esterase polygalacturonase, ß-galactosidase, and cellulose in the later stages of storage. It also downregulated the transcriptional expression of related genes like VcPE, VcPG, VcBG6, and VcGAL1. Thus, MT prevented softening and senescence by postponing the degradation of the cell wall in postharvest blueberry fruit.

Spinal cord repair is modulated by the neurogenic factor Hb-egf under direction of a regeneration-associated enhancer.

Unlike adult mammals, zebrafish regenerate spinal cord tissue and recover locomotor ability after a paralyzing injury. Here, we find that ependymal cells in zebrafish spinal cords produce the neurogenic factor Hb-egfa upon transection injury. Animals with hb-egfa mutations display defective swim capacity, axon crossing, and tissue bridging after spinal cord transection, associated with disrupted indicators of neuron production. Local recombinant human HB-EGF delivery alters ependymal cell cycling and tissue bridging, enhancing functional regeneration. Epigenetic profiling reveals a tissue regeneration enhancer element (TREE) linked to hb-egfa that directs gene expression in spinal cord injuries. Systemically delivered recombinant AAVs containing this zebrafish TREE target gene expression to crush injuries of neonatal, but not adult, murine spinal cords. Moreover, enhancer-based HB-EGF delivery by AAV administration improves axon densities after crush injury in neonatal cords. Our results identify Hb-egf as a neurogenic factor necessary for innate spinal cord regeneration and suggest strategies to improve spinal cord repair in mammals.

Cuticular Wax Triterpenes Maintain Storage Quality of Blueberries by Reducing Water Loss.

Cuticular wax contributes to maintaining postharvest storage quality against fruit water loss and softening. Triterpenoids, such as oleanolic acid (OA) and ursolic acid (UA), are the main components in blueberry cuticular wax, but their role in water migration during the storage of blueberries remains to be determined. Here, we examined the relationship between the content of OA and UA and the storage quality of blueberry fruit (25 °C). The results revealed that the UA content during eight-day postharvest storage ranged from 58 to 77 µg cm-2, which was negatively related to weight loss. Additionally, we investigated the effect of exogenous OA and UA on water migration in the blueberry fruit during storage at room temperature; the weight loss was significantly lower (by 22%) with UA treatment than in the control fruit. Our findings indicate that OA and UA effectively affect water migration in blueberry fruit during postharvest storage, which could contribute to improving postharvest preservation techniques.

Ursolic acid, the main component of blueberry cuticular wax, inhibits Botrytis cinerea growth by damaging cell membrane integrity.

Cuticular wax has been reported to play an essential role in resisting pathogens in various fruits. This study investigated the antifungal ability of the components in blueberry cuticular wax. We showed that the cuticular wax of blueberry inhibited the growth of Botrytis cinerea and ursolic acid (UA) was the key antifungal compound. UA inhibited B. cinerea growth in vitro and in vivo. Furthermore, UA increased extracellular conductivity and cellular leakage in B. cinerea, deformed the mycelial morphology, and destroyed cell ultrastructure. We also demonstrated that UA stimulated the accumulation of reactive oxygen species (ROS) and inactivated ROS scavenging enzymes. These results indicate that UA may exert antifungal effects against B. cinerea by disrupting cell membrane integrity. Thus, UA has significant potential as an agent for the control of gray mold in blueberry.

Recent advances in Zizania latifolia: A comprehensive review on phytochemical, health benefits and applications that maximize its value.

Zizania latifolia is an aquatic and medicinal plant with a long history of development in China and the East Asian region. The smut fungus "Ustilago esculenta" parasitizes Z. latifolia and induces culm expansion to form a vegetable named Jiaobai, which has a unique taste and nutritional attributes. However, the postharvest quality of water bamboo shoots is still a big challenge for farmers and merchants. This paper traced the origin, development process, and morphological characteristics of Z. latifolia. Subsequently, the compilation of the primary nutrients and bioactive substances are presented in context to their effects on ecology a postharvest storage and preservation methods. Furthermore, the industrial, environmental, and material science applications of Z. latifolia in the fields of industry were discussed. Finally, the primary objective of the review proposes future directions for research to support the development of Z. latifolia industry and aid in maximizing its value. To sum up, Z. latifolia, aside from its potential as material it can be utilized to make different productions and improve the existing applications. This paper provides an emerging strategy for researchers undertaking Z. latifolia.

Composition, metabolism and postharvest function and regulation of fruit cuticle: A review.

The cuticle of plants, a hydrophobic membrane that covers their aerial organs, is crucial to their ability to withstand biotic and abiotic stressors. Fruit is the reproductive organ of plants, and an important dietary source that can offer a variety of nutrients for the human body, and fruit cuticle performs a crucial protective role in fruit development and postharvest quality. This review discusses the universality and diversity of the fruit cuticle composition, and systematically summarizes the metabolic process of fruit cuticle, including the biosynthesis, transport and regulatory factors (including transcription factors, phytohormones and environmental elements) of fruit cuticle. Additionally, we emphasize the postharvest functions and postharvest regulatory technologies of fruit cuticle, and propose future research directions for fruit cuticle.

Advances of stable isotope technology in food safety analysis and nutrient metabolism research.

Food quality, safety, and the regulatory metabolism of food nutrients in cells are primary factors in determining human health. However, residues of undesirable or hazardous compounds in food products and dysregulation in the nutrient metabolism inevitably occur occasionally. For years, chromatography-mass spectrometry technology has been recognized as an essential research tool in food analysis and nutrient metabolism research, and it is more accurate and robust when coupled with stable isotopes. In this study, we summarize the applications of stable isotope technology in the quantification of contaminant residues (pesticides, veterinary drugs, mycotoxins, polycyclic aromatic hydrocarbons, and other hazardous compounds) in foods and in the nutrients (glucose, lipids, amino acids and proteins) metabolism research. The aim of this review was to serve as a reference for providing effective analysis techniques for protecting food quality and human health, and to pave the way for the broader application of stable isotope technology.

Exogenous salicylic acid regulates organic acids metabolism in postharvest blueberry fruit.

Fruit acidity is an essential factor affecting blueberry organoleptic quality. The organic acid content in blueberry fruit mainly contributes to fruit acidity. This study aims to evaluate the effect of exogenous salicylic acid (SA), the principal metabolite of aspirin, on the organoleptic quality and organic acid metabolism in rabbiteye blueberry (Vaccinium virgatum Ait, 'Powderblue') during cold storage (4 °C). Results showed that SA-treated fruit reduced fruit decay and weight loss delayed fruit softening, and decline of total soluble solids (TSS). TA and total organic acid amounts stayed the same during the late storage period in SA-treated fruit. Four kinds of organic acid components, malic acid, quinic acid, citric acid, and succinic acid, were at higher levels in fruit treated by SA as compared to control. SA enhanced the activities of PEPC, NAD-MDH, and CS to promote the synthesis of malic acid and citric acid. Meanwhile, the activities of NADP-ME, ACL, and ACO, which participated in the degradation of malic acid and citric acid, were inhibited by SA. qPCR results also showed that the expression of VcPEPC, VcNAD-MDH, and VcCS genes were upregulated. In contrast, SA downregulated the expression of VcNADP-ME, VcACL, and VcACO genes. In conclusion, SA could regulate the key genes and enzymes that participated in organic acids metabolism to maintain the freshness of blueberry during cold storage, therefore minimizing the economic loss.

Fibrin-based cardiac patch containing neuregulin-1 for heart repair after myocardial infarction.

Cardiac patch, a scaffold layered on the surface of the heart that can provide mechanical and regeneration support for damaged myocardium, has provided a promising solution to treat severe myocardial infarction (MI). In this work, a fibrin based cardiac patch loaded with neuregulin-1 (NRG-1) is developed to attach locally to the infract area of heart. The composite patch exhibited good biocompatibility and promoted cardiomyocyte proliferation in vitro via NRG-1/ErbB signaling. Moreover, implantation of this patch to the infracted border zone reduced cell apoptosis, promoted angiogenesis and inhibited fibrosis, which reduced infraction size and improved cardiac function consequently. Thus, the combination of natural biomaterial fibrin and bioactive factor NRG-1 might have a promising potential for clinical application of MI treatment.

Co-encapsulation of chlorogenic acid and cinnamaldehyde essential oil in Pickering emulsion stablized by chitosan nanoparticles.

Most of the current research only explored the loading of an active substance in active packaging. In this study, cinnamaldehyde essential oil (CEO) and chlorogenic acid (CA) were co-encapsulated in chitosan (CS) nanoparticles based Pickering emulsion. The morphology and wettability of CS-CA particles were determined. In addition, physicochemical characterizations and stability of the Pickering emulsion were also investigated. Results showed that the wettability of nanoparticles was improved with increasing the ratios of CS to CA, which is helpful to stabilize the emulsion. CEO Pickering emulsion was stabilized by CS-CA nanoparticles and CEO emulsion showed the best stability by using CS-CA nanoparticles with the ratios of CS to CA 1:0.75 with the minimum creaming index value of 26.5 ± 4.6% after 5 days of storage. These overall results presented in this work demonstrate, for the first time, the potential of Pickering emulsion for the co-encapsulation of water-soluble and water-insoluble ingredients.

Impact of melatonin application on lignification in water bamboo shoot during storage.

Melatonin, a crucial bioactive molecule, involved in several physiological processes in plants. This study investigated the effects of melatonin (MT) treatment on lignification, including firmness, lignin, lignified-enzyme activities, the expression patterns of genes encoding corresponding enzymes and transcription factors in water bamboo shoot during storage for 8 days. MT treatment decreased the firmness and content of lignin. It inhibited the degradation of total phenols and ascorbic acid and delayed the lignin biosynthesis, via reducing the activities of phenylalanine ammonia-lyse cinnamyl alcohol dehydrogenase and peroxidase, as well as lignin biosynthesis-related genes expression levels. Transcription factors of ZlNAC1, ZlNAC2, ZlNAC3 and ZlNAC4 from NAC family and ZlMYB1 and ZlMYB2 from MYB family were increased in water bamboo shoot after harvest and MT-treated markedly reduced their expression. Therefore, our findings supply a fundamental understanding of MT treatment suppression of lignification and establish a foundation for further research on transcriptional regulation.

Generation of specialized blood vessels via lymphatic transdifferentiation.

The lineage and developmental trajectory of a cell are key determinants of cellular identity. In the vascular system, endothelial cells (ECs) of blood and lymphatic vessels differentiate and specialize to cater to the unique physiological demands of each organ1,2. Although lymphatic vessels were shown to derive from multiple cellular origins, lymphatic ECs (LECs) are not known to generate other cell types3,4. Here we use recurrent imaging and lineage-tracing of ECs in zebrafish anal fins, from early development to adulthood, to uncover a mechanism of specialized blood vessel formation through the transdifferentiation of LECs. Moreover, we demonstrate that deriving anal-fin vessels from lymphatic versus blood ECs results in functional differences in the adult organism, uncovering a link between cell ontogeny and functionality. We further use single-cell RNA-sequencing analysis to characterize the different cellular populations and transition states involved in the transdifferentiation process. Finally, we show that, similar to normal development, the vasculature is rederived from lymphatics during anal-fin regeneration, demonstrating that LECs in adult fish retain both potency and plasticity for generating blood ECs. Overall, our research highlights an innate mechanism of blood vessel formation through LEC transdifferentiation, and provides in vivo evidence for a link between cell ontogeny and functionality in ECs.