Search Results (154)

Photodynamic inactivation (PDI) is an innovative non-thermal sterilization and preservation method that has recently emerged as a safe, effective, cost-effective and environmentally sustainable alternative for biomedical applications. Curcumin (Cur), a commonly used food additive, possesses photosensitizing properties. In this study, we investigated the effect of curcumin-mediated photodynamic treatment (Cur-PDT) on the preservation of fresh wolfberries. Our experimental data revealed that a Cur-PDT treatment using a cur concentration of 500 μmol/L for 30 min, with 20 W irradiation, achieved the best preservation effect on fresh wolfberries. This intervention significantly slowed the decline in post-harvest hardness and delayed the progression of decay. It also reduced the accumulation of malondialdehyde (MDA), hydrogen peroxide (H₂O₂) and superoxide anion (•O₂⁻). Notably, at day 3, the enzymatic activities of catalase (CAT) and ascorbate peroxidase (APX) in Cur-PDT-treated wolfberries were 1.12 and 1.88 times higher, respectively, than those in the control group. These elevated enzyme activities promoted the biosynthesis and recycling of ascorbic acid (AsA) and glutathione (GSH), leading to their substantial accumulation under oxidative stress conditions. By modulating the antioxidant defense system, Cur-PDT has the potential to extend the shelf-life of post-harvest wolfberries and enhance their overall quality attributes, thereby maintaining physiological homeostasis during storage. Full article

Potato tuber (Solanum tuberosum L.) was prone to greening and quality deterioration during postharvest storage due to various factors, affecting the regulation of chlorophyll biosynthesis. In the present study, potato tubers were placed at 600 lux and 25 °C after sodium alginate—xanthan gum—glycerin composite coating. During storage, the apparent color changes and a* value of the surface were observed and determined, meanwhile the contents of nutrients, chlorophyll, and its intermediates in photosynthetic metabolism were analyzed. The results showed that after 9 d, compared to the control group, the sodium alginate coating treatment significantly inhibited greening, delayed the decline of appearance quality and nutrients including dry matter, starch, reducing sugar, soluble protein, and ascorbic acid. Furthermore, the sodium alginate coating promoted the contents of 5-aminolevulinic acid (ALA) (1.33 fold), porphobilinogen (PBG) (1.06 fold), and uroporphyrinogen III (Uro III) (1.07 fold), meanwhile, inhibited the production of protoporphyrin IX (Proto IX) (13.86%), Mg-protoporphyrin IX (Mg-Proto IX) (14.15%) and protochlorophyllide (Pchlide) (25.97%), which were key intermediates in the chlorophyll synthesis, indicating that the sodium alginate coating delay the greening by blocking the conversion of Uro III to Proto IX. These results provided valuable insights for the postharvest preservation of potato tuber. Full article

The escalating demand for sustainable agriculture calls for innovative strategies that enhance crop resilience while minimizing dependence on synthetic fertilizers. This study evaluated the synergistic effects of a microbial consortium (PYS), organic fertilizer (OF), glycine (Gly), and indole-3-acetic acid (IAA) on lettuce under heat stress. The experiment was conducted in a greenhouse in Bangkok, Thailand, simulating tropical high-temperature conditions. The PYS+OF+Gly treatment significantly improved fresh weight, matching the performance of chemical fertilizer (CF) and indicating a strong growth-promoting synergy. Chlorophyll a, chlorophyll b, and carotenoid contents were higher in PYS or PYS+OF treatment, suggesting enhanced photosynthetic efficiency. At 60 days, PYS-based treatments also led to substantial increases in total phenolics and flavonoids, coupled with reduced lipid peroxidation and elevated antioxidant activities (DPPH, APX, CAT, POD, and SOD). However, vitamin C levels remained highest in the CF and OF controls, indicating a potential metabolic shift toward phenylpropanoid rather than ascorbate biosynthesis. Overall, our results demonstrate that combining microbial consortia with organic and biostimulant inputs could enhance growth, stress tolerance, and the nutritional quality of lettuce. This integrated approach presents a promising strategy for climate-resilient crop production and warrants further validation across different crops, environmental settings, and large-scale agricultural systems. Full article

Mung bean (Vigna radiate) sprouts are a popular choice among sprouted vegetables in Asia. Currently, the impact of nitrogen sources on the growth of mung bean sprouts remains poorly understood, and the underlying biological mechanisms responsible for the observed nonlinear growth patterns at different nitrogen levels have yet to be elucidated. In this research, in addition to conventional growth monitoring and quality evaluation, a comparative proteomics method was applied to investigate the molecular mechanisms of mung bean in response to 0, 0.025, 0.05, 0.075, and 0.1% urea concentrations. Our results indicated that mung bean sprout height and yield increased with rising urea concentrations but were suppressed beyond the L3 level (0.075% urea). Nitrate nitrogen and free amino acid content rose steadily with urea levels, whereas protein content, nitrate reductase activity, and nitrite levels followed a peak-then-decline trend, peaking at intermediate concentrations. Differential expression protein analysis was conducted on mung bean sprouts treated with different concentrations of urea, and more differentially expressed proteins participated in the L3 urea concentration. Analysis of common differential proteins among comparison groups showed that the mung bean sprouts enhanced their adaptability to urea stress environments by upregulating chlorophyll a-b binding protein and cationic amino acid transporter and downregulating the levels of glycosyltransferase, L-ascorbic acid, and cytochrome P450. The proteomic analysis uncovered the regulatory mechanisms governing these metabolic pathways, identifying 47 differentially expressed proteins (DEPs) involved in the biosynthesis of proteins, free amino acids, and nitrogen-related metabolites. Full article

Tissue engineering enables autologous reconstruction of human tissues, addressing limitations in tissue availability and immune compatibility. Several tissue engineering techniques, such as self-assembly, rely on or benefit from extracellular matrix (ECM) secretion by fibroblasts to produce biomimetic scaffolds. Models have been developed for use in humans, such as skin and corneas. Ascorbic acid (vitamin C, AA) is essential for collagen biosynthesis. However, AA is chemically unstable in culture, with a half-life of 24 h, requiring freshly prepared AA with each change of medium. This study aims to demonstrate the functional equivalence of 2-phospho-L-ascorbate (2PAA), a stable form of AA, for tissue reconstruction. Dermal, vaginal, and bladder stroma were reconstructed by self-assembly using tissue-specific protocols. The tissues were cultured in a medium supplemented with either freshly prepared or frozen AA, or with 2PAA. Biochemical analyses were performed on the tissues to evaluate cell density and tissue composition, including collagen secretion and deposition. Histology and quantitative polarized light microscopy were used to evaluate tissue architecture, and mechanical evaluation was performed both by tensiometry and atomic force microscopy (AFM) to evaluate its macroscopic and cell-scale mechanical properties. The tissues produced by the three ascorbate conditions had similar collagen deposition, architecture, and mechanical properties in each organ-specific stroma. Mechanical characterization revealed tissue-specific differences, with tensile modulus values ranging from 1–5 MPa and AFM-derived apparent stiffness in the 1–2 kPa range, reflecting the nonlinear and scale-dependent behavior of the engineered stroma. The results demonstrate the possibility of substituting AA with 2PAA for tissue engineering. This protocol could significantly reduce the costs associated with tissue production by reducing preparation time and use of materials. This is a crucial factor for any scale-up activity. Full article

Peach fruit faces severe postharvest losses due to thin epidermis and susceptibility to Rhizopus stolonifer-induced soft rot. Chemical control risks residue and resistance issues, demanding eco-friendly alternatives. This study elucidated the mechanism by which trans-2-hexenal (E2H) mitigated postharvest soft rot caused by Rhizopus stolonifer in peach (Prunus persica cv. Hujing Milu) fruit. The results demonstrated that E2H treatment significantly delayed lesion expansion by 44.7% and disease incidence by 23.9% while effectively maintaining fruit quality by delaying firmness loss, reducing juice leakage, and suppressing malondialdehyde (MDA) accumulation. E2H treatment upregulated phenylpropanoid pathway gene expression, enhancing key phenylpropanoid metabolism enzymes activities (phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), 4-coumarate-CoA ligase (4CL), polyphenol oxidase (PPO), peroxidase (POD)), leading to the increase of total phenolics by 7.9%. E2H treatment analysis revealed significant enhancements in both chitinolytic activity (CHI) and β-1,3-glucanase (GLU) activity by 85.7% and 12.9%, indicating potentiation of the enzymatic defense system. Concurrently, E2H treatment could improve the redox modulation capacity of peach fruits through promoting catalytic efficiency of redox-regulating enzymes, increasing the accumulation of ascorbic acid (AsA) by 8.1%, inhibiting the synthesis of dehydroascorbic acid (DHA) by 18.6%, as well as suppressing the biosynthesis of reactive oxygen species (ROS). These coordinated enhancements in pathogenesis-related proteins (CHI, GLU), phenylpropanoid metabolism activation, and antioxidant systems are strongly associated with E2H-induced resistance against Rhizopus stolonifer, though contributions from other factors may also be involved. Full article

Pomegranates are rich in nutrients and classified among ready-to-eat fruits and vegetables. Although this ready-to-eat produce offers convenience, it presents risks associated with pathogenic microorganisms, highlighting the need for pre-sale disinfection. Ultraviolet light-emitting diodes (UV-LEDs) constitute an innovative non-thermal processing technology for food products, offering reduced heat generation and lower energy consumption compared to traditional ultraviolet (UV) irradiation methods. This study analyzed the effects of UV-LED technology on pomegranate seed quality over 0 to 5 days of storage. The results demonstrated significant increases in anthocyanins, polyphenols, ascorbic acid, and the antioxidant capacity in pomegranate following treatment, peaking on day 3. In contrast, the control group showed declining trends. After treatment, the aerobic mesophilic counts and counts of mold and yeast levels during storage measured between 2.73–3.23 log CFU/g and 2.56–3.29 log CFU/g, respectively, significantly lower than the control group. Non-targeted metabolomic analysis showed that UV-LED treatment prompted modifications in the biosynthetic pathways of flavonoids, flavonols, and anthocyanins. The expression of peonidin-3-O-rutinoside chloride increased by 46.46-fold within the anthocyanin biosynthesis pathway. In conclusion, UV-LED treatment represents a potential approach to the disinfection of ready-to-eat fruits and vegetables. Full article

Pyrus bretschneideri ‘Xinli No.7’, a progeny of Pyrus sinkiangensis ‘Korla Fragrant Pear’, is an early-maturing, high-quality pear (Pyrus spp.) cultivar. As a dominant variety in China’s pear-producing regions, it holds significant agricultural importance. Investigating its male sterility (MS) mechanisms is critical for hybrid breeding and large-scale cultivation. Integrated cytological, physiological, and transcriptomic analyses were conducted to compare dynamic differences between male sterility (MS, ‘Xinli No.7’) and male-fertile (MF, ‘Korla Fragrant Pear’) plants during anther development. Cytological observations revealed that, compared with ‘Korla Fragrant Pear’, the tapetum of ‘Xinli No.7’ exhibited delayed degradation and abnormal thickening during the uninucleate microspore stage. This pathological alteration compressed the microspores, ultimately leading to their abortion. Physiological assays demonstrated excessive reactive oxygen species (ROS) accumulation, lower proline content, higher malondialdehyde (MDA) levels, and reduced activities of antioxidant enzymes (peroxidase and catalase) in MS plants. Comparative transcriptomics identified 283 co-expressed differentially expressed genes (DEGs). Functional enrichment linked these DEGs to ROS-scavenging pathways: galactose metabolism, ascorbate and aldarate metabolism, arginine and proline metabolism, fatty acid degradation, pyruvate metabolism, and flavonoid biosynthesis. qRT-PCR validated the expression patterns of key DEGs in these pathways. A core transcriptome-mediated MS network was proposed, implicating accelerated ROS generation and dysregulated tapetal programmed cell death. These findings provide theoretical insights into the molecular mechanisms of male sterility in ‘Xinli No.7’, supporting future genetic and breeding applications. Full article

Cadmium (Cd) is a highly hazardous heavy metal that has an extensive impact throughout the world. 2,4-Epibrassinolide (BR) is an endogenous hormone that can enhance plant tolerance to various abiotic stresses. Herein, Vigna angularis cultivar “Zhen Zhuhong” was grown hydroponically and treated with 0, 1, and 2 mg·L⁻¹ cadmium chloride (CdCl₂) at the V1 stage, and foliar sprayed with or without 1 μM BR solution to analyze the effects of BR treatment on the physiology of Vigna angularis seedling leaves under Cd stress. BR treatment significantly alleviated the growth inhibition induced by Cd stress, which was associated with an increase in the plant height (11.15–17.83%), leaf area (35.59–56.72%), leaf dry weight (45.57–50.65%), and above-ground dry weight (50.86–55.17%). In addition, BR treatment induced significant reductions in Cd accumulation across different tissues of V. angularis, with decreases of 20.38–35.93% in leaves, 21.24–32.74% in stems, and 15.38–16.00% in petioles. Compared with the Cd treatment, BR treatment significantly enhanced the activities of peroxidase (5.02–13.22%), ascorbate peroxidase (27.13–70.28%), catalase (20.46–32.30%), and superoxide dismutase (16.54–21.81%), and increased the ascorbic acid content (27.55–45.52%), which contributed to a reduction in the accumulation of reactive oxygen species, cellular membrane damage, and cytoplasmic exosmosis. RNA-seq and real-time quantitative reverse transcription PCR analyses revealed that the BR treatment under Cd stress significantly upregulated the expression of genes involved in chlorophyll biosynthesis, transformation, and degradation, thereby enhancing the chlorophyll cycle. Furthermore, the BR treatment significantly increased the number of grana lamellae in the mesophyll cells, which enhanced the biosynthesis of chloroplasts. The increase in the chlorophyll content improved the capture of light energy, electron transport in photosynthesis, and the biosynthesis and metabolism of carbohydrates in the leaves of V. angularis under Cd stress. Full article

In northern China’s arid and semi-arid regions, evergreen trees demonstrate significant cold tolerance to natural low-temperature stress during winter. However, the metabolic strategies and their associated properties underlying their overwintering adaptation remain incompletely elucidated. This study aims to reveal the metabolic properties of natural low-temperature adaptation strategies in five evergreen trees through metabolomic analysis and to identify key metabolites and their dynamic variation patterns. The GC-TOF-MS platform was used to investigate seasonal differential metabolites in five evergreen trees across January, April, July, and October and further explore core differentially expressed metabolites responsive to low-temperature stress. The results demonstrated that the seasonal changes in the chlorophyll content of five evergreens exhibited distinct patterns, that significant differences were observed between Juniperus sabina L. and Picea meyeri R., Ammopiptanthus mongolicus M., Buxus sinica var. parvifolia M.Cheng, and Pinus tabuliformis C., and that no significant differences were found among the other tree species. A total of 427 metabolites were detected in the metabolome; when assessing seasonal dynamics, it was found that the types of differentially expressed metabolites in the five evergreens underwent significant changes. In spring, the differentially expressed metabolites included some carbohydrates, alcohols, organic acids, and lipids. During summer and autumn, the largest number of differentially expressed metabolites accumulated, mainly including carbohydrates, organic acids, and amino acid compounds. In winter, while Picea meyeri primarily accumulated carbohydrates, the remaining four species mainly accumulated organic acids, along with a small number of alcohols, phenylpropanoids, and polyketides. Three shared carbohydrate metabolites, L-threose, galactinol, and gluconic lactone, were commonly downregulated across all species. Additionally, coniferous trees collectively accumulated 3,6-anhydro-D-galactose, showing downregulation. The KEGG enrichment analysis of winter-accumulated metabolites revealed significant associations with the pentose phosphate pathway, amino acid metabolism, phenylpropanoid biosynthesis, the tricarboxylic acid cycle, and ascorbate–aldarate metabolism pathways. Through comparative analysis with the summer growth season, we ultimately identified the core differentially expressed metabolites of the five evergreens, providing potential metabolic markers for the breeding of cold-tolerant species. In summary, these findings provide critical metabolomic insights into how plants adapt to low temperatures, significantly enhancing our understanding of the metabolic foundations of cold tolerance in evergreen species. Full article

Ascorbic acid (AsA) is an essential plant metabolite that acts primarily as an antioxidant, regulates cell division and elongation, and enhances stress tolerance. Despite its crucial physiological role, the biosynthesis of AsA in G. max, a major crop of significant commercial importance, remains largely unexplored. This gap highlights the need for a thorough investigation of AsA biosynthesis pathways and their role in optimizing the nutritional value and stress tolerance of soybeans. This study identified 41 key genes linked to four AsA biosynthesis pathways in G. max, highlighting specific gene duplications compared to Arabidopsis. Their expression levels were assessed by analyzing a diverse set of RNA-Seq data from the NCBI database. Additionally, to cross-validate the expression levels of genes and the accumulation levels of AsA in the principal tissues, G. max plants were grown under controlled conditions following the protocols from selected RNA-seq experiments. Genes associated with the D-mannose/L-galactose pathway exhibited ubiquitous expression, and the expression patterns of genes from alternative pathways reflected their responsiveness to specific tissues or environmental conditions. Germination and leaf development were accompanied by strong expression of gene members from all pathways, whereas leaf aging was characterized by downregulation. Specific gene members, such as GMP_2a (D-mannose/L-galactose pathway), GulLO_1f (L-gulose pathway), and MIOX_3a (Myo-inositol pathway) were highly stress-responsive and linked to stress-resistant genotypes and cultivars. Consistent with gene expression analyses, the quantification of AsA revealed the highest mass fractions in young leaves and germinating seeds. However, AsA mass fractions were significantly reduced or unchanged under stress conditions, depending on the type of stress and the duration of exposure. Overall, this study validated the relevance of AsA biosynthesis pathways in soybeans, highlighting key genes that could be targeted to enhance stress tolerance and improve ascorbate production, thereby boosting the nutritional value of soybeans. Full article

Tea plants (Camellia sinensis) are among the world’s most significant economic tree species. Tissue culture serves as a crucial method in commercial breeding by facilitating the rapid propagation of valuable genotypes and the generation of disease-free clones. However, callus browning represents a prevalent challenge in tea plant tissue culture, and may adversely affect explant growth and development. Our research demonstrates that although anti-browning agents can effectively suppress browning, they induce distinct color changes in the callus. These color variations could significantly influence callus induction and subsequent growth patterns. In this study, callus tissues from C. sinensis var. Assamica cv. Mengku were employed as experimental materials and treated with three commonly used anti-browning agents: ascorbic acid (VC), activated carbon (AC), and polyvinylpyrrolidone (PVP). The results demonstrated that while these three reagents effectively inhibited browning, they also induced distinct color changes in the explants, which appeared red, green, and white, respectively. Furthermore, this study investigated the molecular mechanisms underlying callus color changes using transcriptomic and metabolomic approaches. Based on transcriptome analysis, it was revealed that photosynthesis and flavonoid biosynthesis pathways were significantly enriched. Metabolome analysis identified 14 phenolic acids, which exhibited significant variation in accumulation across calluses of different colors. The differential expression of genes involved in flavonoid biosynthesis pathways, coupled with the distinct accumulation patterns of metabolites, can effectively alleviate photooxidative damage and enhance the resistance of callus to browning. AC activates the photosynthesis of callus by regulating carbon source allocation and upregulating the expression of key genes in the psa, psb, and pet families within the photosynthetic system. This process promotes chlorophyll biosynthesis, thereby enabling the callus to grow green, while VC activates the expression of key genes such as CHS, F3H, C4H, CYP75B1, and ANR in the flavonoid pathway, which are involved in the regulation of pigment synthesis in red callus. This study elucidated the molecular mechanisms underlying the effects of anti-browning agents on color variations in C. sinensis callus, thereby providing a robust theoretical foundation for optimization, the establishment of tea plant tissue culture systems, and enhancing cultivar quality. Full article

Drought deficit inhibits oat growth and yield. Fulvic acid (FA) can enhance plant stress tolerance, but its effects on regulating the ascorbate–glutathione cycle, chlorophyll synthesis, and carbon–assimilation ability remain unclear. Therefore, this study aimed to elucidate the physiological mechanisms of the FA regulation of drought tolerance in oats and its relationship with growth and yield using the drought-resistant variety Yanke 2 and the drought-sensitive variety Bayou 9. The effects of FA on growth and yield, the antioxidant system, chlorophyll synthesis, and carbon–assimilation capacity of oats under drought stress were investigated by systematically assessing changes in morphogenesis, ascorbate–glutathione cycle, chlorophyll and its intermediates, carbon–assimilation enzyme activities, and carbohydrate metabolism. The results showed that under drought stress, FA treatment significantly promoted oat growth (leaf area, dry matter) and yield, elevated glutathione peroxidase, ascorbate peroxidase, glutathione reductase, and dehydroascorbate reductase activities, reduced ascorbic acid, and reduced glutathione content. In addition, FA increased chlorophyll, as well as magnesium protoporphyrin IX, protoporphyrin IX, and protochlorophyllin acid ester content, enhanced 1,5-bisphosphate ribulose carboxylase, 1,5-bisphosphate ribulose carboxylase enzyme, 1,7-bisphosphate sestamibiose heptulose esterase, 1,6-bisphosphate fructose aldolase, sucrose synthase, sucrose phosphate synthase, acid invertase, and neutral invertase activities, and increased sucrose, glucose, and fructose content. Overall, fulvic acid (FA) alleviates drought-induced damage in oats by enhancing the ascorbate–glutathione cycle, promoting chlorophyll biosynthesis, and improving carbon assimilation and carbohydrate metabolism. The drought-sensitive variety (Yanke 2) was more effective in application compared to the drought-resistant variety (Bayou 9). This research provides valuable insight into its potential as a biostimulant under abiotic stress. Full article

Selenium (Se) is an essential trace element for humans, and the production of Se-enriched rice (Oryza sativa) is a key approach for Se supplementation. Nevertheless, the effects of different Se forms and concentrations on the metabolism and aboveground absorption pathways of rice seedlings are not yet well-understood. Therefore, we conducted a hydroponic experiment and used transcriptome analysis to study the absorption and transformation processes of sodium selenite (Na₂SeO₃) and selenomethionine (SeMet) in rice at the seedling stage. The aboveground (stem + leaf) Se concentration at the seedling stage was higher under the SeMet treatments, and low Se applications (<25 μM) significantly promoted rice growth. Selenocysteine (SeCys) and SeMet were the primary forms of Se in rice, accounting for 57–86.35% and 7.6–31.5%, respectively, while selenate [Se (VI)] significantly increased when Se levels exceeded 25 μM. In the transcriptome, differentially expressed genes (DEGs) were significantly enriched in the following pathways: carbon metabolism, amino acid biosynthesis, and glutathione metabolism. In the Na₂SeO₃ treatments, genes encoding phosphoglycerate mutase (PGM), triosephosphate isomerase (TPI), phosphofructokinase (PFK), pyruvate kinase (PK), malate dehydrogenase (MDH), polyamine oxidase (PAO), aspartate aminotransferase (AST), and glutathione S-transferase (GST) were upregulated, and the expression levels of differentially expressed genes (DEGs) decreased with increasing Se levels. SeMet treatments upregulated genes encoding PFK, PK, glutamine synthetase (NADH-GOGAT), and L-ascorbate peroxidase (APX), and expression levels of DEGs increased with increasing Se levels. This study provides important insights into the molecular mechanisms of the uptake and metabolism of different Se forms in rice at the seedling stage. Full article

‘Shannongsu’ pear is a new high-quality cultivar. To ascertain the storage characteristics of ‘Shannongsu’ pears at low temperatures (0 ± 0.5 °C), the following parameters were determined: fruit firmness, ethylene, aromatic compounds, sugar content, acidity, ascorbic acid, and the expression levels of ethylene-related genes and texture-softening genes. The firmness of ‘Shannongsu’ pears changed less than that of the control, decreasing by only 18.8% after 170 days of storage. Low temperatures suppressed the expression of key genes associated with PbACS1a and PbACO1. Moreover, the expression of key genes related to fruit softening (PbPG1, PbXET, PbPME, and Pbα-L-Af) was suppressed during storage at low temperatures and remained at low levels. Therefore, the low levels of ethylene biosynthesis and the expression of key genes involved in fruit softening might play a major role in the excellent storage characteristics of the ‘Shannongsu’ cultivar. After 170 days of storage, ‘Shannongsu’ pears did not show significant changes in key quality dimensions such as firmness, sugar, acid, sugar–acid ratio, and ascorbic acid content. Therefore, low temperatures could help maintain the freshness, flavor, and nutritional quality of the ‘Shannongsu’ pear. Our findings reveal for the first time the low-temperature storage characteristics of ‘Shannongsu’ pears, providing a new scientific theoretical basis for pear production and marketing. Full article