Search Results (1,139)

Biodegradable alginate films containing silver nanoparticles (AgNPs) are being increasingly investigated as active agricultural materials (e.g., antimicrobial mulches) and active food packaging. However, since these materials ultimately degrade in soil after use, assessing their environmental compatibility and potential phytotoxicity upon release is crucial. The aim of this study was to synthesize films containing AgNPs in sodium alginate using xylose as a reducing agent and to determine their effect on culturable rhizosphere microorganisms and selected biochemical parameters in young arugula (Eruca vesicaria L. subsp. sativa) plants. Alginate films containing three nominal AgNP loadings (50, 100, and 150 mg L⁻¹) and a control film without AgNPs were synthesized. The films were cut into square pieces (4 cm²) and placed in 0.076 L multipots filled with peat substrate, into which arugula seeds were sown. During the experiment, the abundance of culturable rhizosphere bacteria and fungi was determined, and the young arugula plants were subjected to biochemical analyses. The results showed that the AgNP-containing films did not significantly affect the abundance of bacteria and fungi in the rhizosphere under the conditions tested. The tested films also did not markedly alter the measured parameters in the tissues of young arugula plants, including ascorbic acid, photosynthetic pigments, sugars, dietary protein, and glutathione. However, they reduced phenolic content, altered antioxidant activity, and led to detectable silver accumulation in plant tissues, especially at the highest nominal AgNP loading (150 mg L⁻¹). These findings indicate limited but selective biochemical effects during the early growth stage of arugula rather than a complete absence of plant response. Full article

Hibiscus plant cell cultures were developed to produce a cosmetic ingredient with anti-ageing properties. UHPLC-DAD-MS analysis of Hibiscus plant cell cultures revealed a high content of polyphenols, particularly hydroxycinnamic acid derivatives, including caffeoyl and p-coumaroyl conjugates. The biological activity of a 50/50 mixture of extracts from Hibiscus syriacus and Hibiscus rosa-sinensis cells was investigated in a human keratinocyte/fibroblast co-culture model, which better reproduces the reciprocal epithelial–mesenchymal interactions between epidermal keratinocytes and dermal fibroblasts than monocultures, using quantitative data-independent acquisition (DIA) LC-MS/MS proteomics combined with functional enrichment and protein–protein interaction analyses. A total of 7062 proteins were identified, of which 280 were differentially expressed (107 upregulated and 171 downregulated) following hibiscus treatment. The proteomic profile suggested coordinated molecular reprogramming associated with extracellular matrix remodelling, tissue repair, hydration, and attenuation of inflammatory signalling. Functional enrichment analysis revealed coordinated modulation of extracellular matrix organization, glycosaminoglycan metabolism, lysosomal function, cell communication, and inflammatory signalling. Upregulation of extracellular matrix and adhesion proteins, including lumican, collagen VIII, fibulin-5, syndecans, and glypicans, suggested coordinated extracellular matrix remodelling that may promote skin firmness and elasticity, while the downregulation of inflammatory regulators, including CARD16 and S100 family proteins, suggested attenuation of innate inflammatory responses. Overall, these findings provide mechanistic insights into the biological activity of Hibiscus cell culture extracts and support their potential as cosmetic ingredients promoting skin homeostasis and healthy skin ageing. Full article

Juniperus species are a rich source of pharmacologically important secondary metabolites, including terpenoids, lignans, flavonoids, and phenolic compounds. However, the commercial utilization of these metabolites is limited by the plant’s slow growth, poor natural regeneration, and environmental variability affecting metabolite accumulation. Integrating plant tissue culture with elicitation strategies is a promising approach for sustainably producing these valuable compounds. This review summarizes the diversity, biological activities, and biotechnological significance of secondary metabolites in Juniperus, focusing on tissue culture systems and enhancement of metabolite biosynthesis through elicitors. It critically evaluates the current knowledge of the effects of signaling compounds such as methyl jasmonate (MeJA), jasmonic acid (JA), and salicylic acid (SA), as well as other abiotic and biotic elicitors including silver nanoparticles (AgNPs), chitosan, and chito-oligosaccharides. Particular attention is given to their effects on podophyllotoxin, phenolic, flavonoid, and other bioactive metabolite accumulation. Elicitation responses appear to depend strongly on species, culture system, elicitor type, and treatment conditions. This review also highlights major knowledge gaps, particularly the limited understanding of the regulatory mechanisms controlling secondary-metabolite biosynthesis in Juniperus species. Overall, the available evidence suggests that integrating optimized elicitation strategies with transcriptomics, metabolomics, and metabolic engineering could improve our understanding of secondary metabolite regulation and facilitate the development of sustainable Juniperus tissue culture platforms for producing high-value natural products. Full article

Panax ginseng, a high-value medicinal plant, faces substantial yield losses due to black spot disease, while conventional chemical controls cause pesticide residues and soil ecological damage, necessitating green biocontrol strategies. Here, two antagonistic strains, Bacillus sp. WY17 and WY26, were isolated from the surface-sterilized internal root tissues of 10-year-old ginseng. Through systematic optimization of carbon/nitrogen sources, inorganic salts, and fermentation parameters (temperature, pH, agitation, inoculum size, and duration), the optimal culture conditions were established. The optimal consortium consisted of WY17 and WY26 in a 2:1 ratio (WY17:WY26 = 2:1), which achieved an antifungal inhibition rate of 84.94% against the pathogen compared to the untreated control group (pathogen only). Mechanistic investigations revealed that the crude protein extract exerted its antifungal effect by compromising the integrity of the pathogen’s cell membrane, leading to increased permeability and leakage of intra-cellular contents, and produced cell wall-degrading enzymes (chitinase and β-1,3-glucanase), thereby inhibiting mycelial growth and spore germination. In vitro efficacy tests demonstrated that this crude protein extract performed comparably to the chemical fungicide 70% mancozeb, with no statistically significant difference observed between them (p > 0.05). These findings identify a promising compound biocontrol agent derived from indigenous Bacillus strains, offering an effective and environmentally friendly alternative for managing ginseng black spot disease. Full article

Medicinal plants remain one of the most important sources of therapeutically relevant compounds for pharmaceutical, nutraceutical, and biotechnological applications. However, the naturally low abundance of many specialized metabolites, considerable phytochemical variability, and increasing environmental pressures continue to limit the sustainable exploitation of plant-derived bioactive compounds. This review summarizes current strategies aimed at identifying, understanding, and enhancing the production of medicinally valuable metabolites while highlighting both biological limitations and emerging technological opportunities. Particular attention is given to the interplay between primary and secondary metabolism and its role in determining biosynthetic efficiency in both natural and engineered systems. Beyond discussing established methodologies, this review adopts a broader perspective by incorporating less frequently addressed aspects, including the influence of climate change on metabolite production, the application of bioinformatics-supported approaches to improve bioprospecting efficiency, and the growing role of nanoparticles as elicitors in plant biotechnology. These topics are considered alongside advances in tissue culture technologies, metabolic engineering, molecular approaches, and systems-level analyses aimed at improving metabolite yield and production stability. Current evidence suggests that no single technological framework is sufficient to address the complexity of medicinal plant metabolism. Hence, rather than presenting individual technologies as isolated solutions to specific biosynthetic bottlenecks, this review emphasizes that medicinal plant metabolism should be considered a highly interconnected system in which environmental, molecular, and physiological factors collectively determine production outcomes. Full article

Waterlilies (Nymphaea spp.) are ecologically and ornamentally important aquatic plants, yet their micropropagation remains challenging due to endophytic contamination and the recalcitrant nature of tuber explants. This study established an efficient in vitro protocol for Nymphaea pubescens using field-collected tubers. Surface sterilization with 0.2% mercuric chloride (HgCl₂) for 15 min achieved complete sterility with 80% explant viability, and an “escape technique” of excising newly emerged shoots from the maternal tuber reduced latent bacterial contamination. Liquid Murashige and Skoog (MS) medium with 1.0 mg/L 6-benzylaminopurine (BAP), 0.1 mg/L thidiazuron (TDZ), and 0.5 mg/L 1-naphthaleneacetic acid (NAA) produced greater shoot multiplication (17.20 ± 2.53 shoots/explant) and elongation (1.03 ± 0.22 cm) than semi-solid medium (9.70 ± 2.11 shoots/explant; 0.70 ± 0.13 cm) (p < 0.01). Transfer to semi-solid maturation medium with glutamine and casein hydrolysate produced the highest survival rate (100%) and significantly improved shoot quality (p < 0.01), mitigating hyperhydricity from prolonged liquid culture. Rooting on semi-solid medium with 0.5 mg/L NAA yielded 90% rooting, and over 80% of acclimatized plantlets established successfully in the field within two weeks. These results provide a practical, reproducible protocol for conservation and mass propagation of N. pubescens and a foundation for future in vitro mutation breeding in ornamental waterlilies. Full article

Plant tissue culture enables the controlled evaluation of plant responses under in vitro conditions, whereas biospeckle laser analysis (BSL) provides a non-invasive approach for assessing dynamic responses in living tissues. However, its application in plant tissue culture requires methodological standardization, particularly in the selection of the illuminated region. This study aimed to standardize BSL acquisition in in vitro grown A. obesum seedlings by comparing the basal, middle, and tip root regions under two contrasting culture medium conditions. Biospeckle responses were quantified using the Absolute Value of the Differences (AVD) index and graphical AVD (GAVD). A significant culture medium × root region interaction was detected for AVD. In MS medium, the basal region showed the highest AVD values, followed by the middle and tip regions, whereas no significant differences among root regions were observed in the medium without mineral salts. The mean root AVD was positively correlated with dry mass, leaf number, fresh mass, leaf length, leaf width, and root length, indicating an association with seedling performance. These findings support the basal region as a suitable candidate for standardized BSL acquisition in A. obesum under the evaluated conditions and demonstrate that root-region selection should be considered during the methodological optimization. Full article

Macadamia (Macadamia spp.) is an economically important nut crop whose severe recalcitrance to genetic transformation substantially hinders progress in functional genomics and molecular breeding. To overcome this critical technical bottleneck, this study established a highly efficient and broadly applicable in planta hairy root genetic transformation system with integrated visual screening. This system utilizes an Agrobacterium rhizogenes-mediated transformation method, employing multiple visual reporter gene systems (DsRed2, eGFP, RUBY, and AtPAP2) to achieve antibiotic-independent and non-destructive screening of transgenic roots. Notably, the system innovatively incorporates the air layering (marcotting) technique to extend in planta genetic transformation to branches of mature trees in the field. By circumventing the stringent sterile conditions required for conventional in vitro tissue culture, this approach achieves a largely genotype-independent transformation across open-pollinated seedlings with diverse genetic backgrounds (A4, GR1, HAES900, and O.C.). The transgenic hairy root induction frequencies ranged from 39.25% to 47.38%, although the GR1 genotype exhibited a notable developmental stage-dependent decline in transformation efficiency. Furthermore, transgenic hairy roots were successfully induced on mature tree branches, with a maximum induction rate of 28.2%. Gene expression analyses confirmed the stable, high-level expression of the target transgenes in all the transgenic hairy root lines. This in planta transformation system provides a reliable in vivo experimental platform for the rapid functional validation of candidate genes and the investigation of root biology in Macadamia. Moreover, it establishes a novel strategy for plant regeneration via root-to-shoot organogenesis, offering a promising avenue for the genetic improvement of recalcitrant woody plants. Full article

PBU (N-phenyl-N′-thiazolylurea) promotes callus induction and adventitious bud differentiation in eucalyptus, but the miRNA-mediated regulatory mechanisms underlying these effects remain unclear. In this study, calli of Eucalyptus urophylla × E. grandis clone DH32-29 with distinct phenotypes were cultured at four PBU concentrations (0, 0.1, 1 and 5 mg L⁻¹) and analyzed by small-RNA sequencing, targeted metabolomics, and qRT-PCR validation. A total of 114 common differentially expressed miRNAs were identified, targeting 610 mRNAs. Functional enrichment analysis revealed that these targets were predominantly associated with lignin metabolism, phenylpropanoid metabolism, biotin metabolism, tryptophan metabolism, protein processing in the endoplasmic reticulum, and galactose metabolism. Metabolomic profiling detected 3029 metabolites, with differential metabolites enriched in the ABC transporter pathway, galloyl sugar biosynthesis, and cofactor biosynthesis. Key miRNA families, including miR164, miR165/166, and miR396, exhibited PBU concentration-dependent expression patterns and were predicted, based on in silico target prediction and qRT-PCR co-expression, to be potentially associated with target genes involved in lignin biosynthesis, ROS-related metabolism, and cytokinin homeostasis; these regulatory relationships remain to be experimentally validated. Among the tested concentrations, 1 mg L⁻¹ PBU was the dosage associated with the strongest reprogramming of secondary metabolism and with metabolic signatures suggestive of better preserved redox homeostasis; future work will build on this reference dataset with quantitative regeneration phenotyping and direct redox measurements to confirm this candidate optimum. These findings provide new insights into PBU-mediated in vitro regeneration in eucalyptus and offer a molecular basis for optimizing regeneration systems in E. urophylla × E. grandis. These findings provide new insights into the miRNA-metabolite regulatory network underlying phenylurea-mediated callus differentiation in woody plants. Full article

This study aimed to establish and optimize an open in-bottle micro-cutting technique for Taxus × media. An orthogonal experimental design was adopted. Four core factors were optimized: light regime, plant growth regulator (PGR) type, PGR concentration, and PGR soaking time. Analysis of variance (ANOVA) and Duncan’s multiple-range test were performed to analyze the statistical significance of each factor. The optimal combination was identified. Branches were soaked in a 300 mg·L⁻¹ IBA solution for 15 min. They were then cultured under 12 h alternating light/dark conditions in an illumination incubator. Under these conditions, the cutting rooting rate reached a maximum of 45.83%. The optimized open tissue culture system established in this study provides reliable technical support for the clonal propagation of T. × media. Full article

Camellia oleifera Abel. is a typical self-incompatible plant, yet its molecular mechanisms have not been comprehensively elucidated, which constitutes the principal cause underlying the relatively low natural fruit set rate in C. oleifera. S-RNase belongs to the RNase T2 gene family and represents a class of glycoproteins specifically expressed in the style with certain “cytotoxicities” capable of degrading ribonucleic acid (RNA) in their own pollen tube cells, thereby inducing programmed cell death in pollen tube cells. To identify pistil S genes participating in the self-incompatibility response of C. oleifera, nine RNase T2 family genes were identified based on transcriptomic and whole-genome sequencing data of the camellia oil tree and designated CoRNS1–CoRNS9. Systematic evolutionary analysis revealed that CoRNS5, CoRNS7, and CoRNS8 exhibit close phylogenetic relationships with S-RNases of the Camelliaceae family, whereas CoRNS6 shows closer affinity with S-RNases of the Solanaceae family. Analysis of promoter cis-acting elements revealed that RNase T2 family genes are regulated by multiple hormones, including abscisic acid, methyl jasmonate, cytokinin, auxin, salicylic acid, and gibberellin, and possess MYB transcription factor-binding sites. Expression analysis revealed that CoRNS6 is expressed exclusively in the ovary; CoRNS5 is expressed at the highest level in the style, followed by lower levels in the petals, anthers, filaments, receptacle, and ovary; CoRNS1 is expressed in all tissues except anthers; and the other genes are expressed across various floral tissues. Ex vitro pollen culture system experiments demonstrated that the CoRNS1 and CoRNS5 recombinant proteins significantly inhibited the elongated growth of autogamous pollen tubes, whereas CoRNS7 significantly reduced the pollen germination rate. Fluorescence labeling revealed that treatment of autogamous pollen tubes with the recombinant proteins CoRNS1, CoRNS5, and CoRNS7 induced microfilament skeleton depolymerization and increased the Ca²⁺ concentration within the pollen tubes. Additionally, treatment with the CoRNS5 recombinant protein increased the reactive oxygen species (ROS) levels in autogamous pollen tubes. These findings suggest that RNase T2 family genes are involved in the self-incompatibility response in C. oleifera, with CoRNS1, CoRNS5, and CoRNS7 playing pivotal roles. Overall, our results not only offer a theoretical foundation for elucidating the regulatory network governing self-incompatibility in C. oleifera, but also furnish valuable genetic resources for future molecular breeding programs targeting improved self-compatibility and increased fruit yield. Full article

Commonly used cytokinins in apple tissue cultures include 6-benzylaminopurine riboside (BAR), thidiazuron (TDZ), and meta-topolin (TOP). In this study, shoots of two distinct apple cultivars (‘Húsvéti rozmaring’ and ‘McIntosh’) were cultured on standard Murashige and Skoog medium supplemented with 4.5 µM of either BAR, TDZ, or TOP, alongside a cytokinin-free control medium. Since comprehensive comparative studies on these specific cytokinins and apple cultivars have not yet been conducted, we evaluated their individual effects on critical enzyme activities, including acid and alkaline phosphatase, β-glycerophosphatase, β-NAD diphosphatase, peroxidase (POD), and polyphenol oxidase (PPO), as well as total phenolic content (TPC) and ferric reducing antioxidant power (FRAP). Substantial changes in both enzymatic activity and antioxidant profiles were clearly detected across both cultivars after any cytokinin treatments in shoots. The highest acid phosphatase (183.0% ± 8.72) and β-glycerophosphatase (191.9% ± 11.95) activities, as well as the highest FRAP (122.9% ± 8.16), were observed in the TOP-treated HR plants. The highest alkaline phosphatase (144.3% ± 5.51) and polyphenol oxidase (204.3% ± 5.07) activities were measured in the BAR-treated HR plants. The highest β-NAD diphosphatase (148.5% ± 5.29) activity was determined in the TDZ-treated HR plants, while the highest peroxidase activity was measured in the control HR and McI plants. The highest TPC (119.7% ± 2.03) was determined in the BAR-treated McI plants. Distinct and notable variations were observed not only among the effects of individual cytokinins, but also between the two apple scions examined. In conclusion, TDZ exhibited consistent stress-like effects, such as the inhibition of shoot and root elongation, whereas TOP effectively maintained the overall physiological balance in the in vitro apple shoot cultures, keeping the photosynthetic pigment content similar to that of the control. Full article

Dendrobium flexicaule has extremely strict requirements for its habitat, and its seeds are small and lack stored nutritional reserves, resulting in an extremely low natural germination rate. Excessive pursuit and excavation of wild D. flexicaule have led to the gradual depletion and a critical situation of endangerment. This study conducted tissue culture and in vitro regeneration of mature seeds of the endangered medicinal plant D. flexicaule, systematically investigating the optimal culture conditions for the regeneration propagation system. The results showed that, for the primary culture of sterile germination in the seed stage, the optimal culture medium was MS medium containing 0.2 mg/L NAA and 80 g/L potato homogenate, with the highest germination rate of 98.33%, and the protocorms grew robustly. The optimal subculture for the proliferation and differentiation of protocorms was MS medium containing 0.5 mg/L NAA and 0.5 mg/L 6-BA, supplemented with 0.5 g/L activated carbon, with a proliferation coefficient of 1.88 and differentiation rate of 81.33%; the clustered buds developed well. The 1/2 MS medium with added 50 g/L banana puree and 1 g/L activated carbon significantly promoted the growth of tissue culture seedlings, suggesting that medium without the addition of plant growth regulators is the optimal formulation for promoting vigorous seedling growth and rooting induction of D. flexicaule tissue culture seedlings. This study established an effective protocol for in vitro tissue culture of D. flexicaule, which is expected to offer valuable technical support for the establishment of rapid propagation and cultivation, relieving its endangered situation of wild resources. Full article

Helichrysum arenarium (L.) Moench is a European native species typically associated with dry, sunny, sandy, and nutrient-poor habitats. In European herbal practice, preparations from H. arenarium inflorescences are traditionally used for the symptomatic relief of digestive complaints. Polyphenolic constituents, particularly flavonoid and chalcone derivatives, are among the most characteristic compounds detected in the inflorescences. Intensive harvesting and degradation of natural habitats have increased pressure on wild populations. Since H. arenarium is legally protected in many countries, biotechnological approaches for plant biomass production represent a promising alternative. In the present study, shoot and callus cultures were established, and detailed extract profiling was performed using ultra-high-performance liquid chromatography coupled with diode-array detection and electrospray ionization multistage mass spectrometry (UHPLC-DAD-ESI-MS³). Cytotoxic, antioxidant, anti-inflammatory, wound-healing, anti-collagenase, and anti-hyaluronidase activities were also evaluated. In vitro-derived materials were compared with inflorescences and shoots of the maternal plant. The analyzed materials showed pronounced tissue-dependent metabolic differentiation. The highest callus growth rate was observed for the Ha-C-1 line, which also accumulated the highest levels of chlorogenic acid (25.80 ± 3.09 mg/g dry extract) and isochlorogenic acid A (55.83 ± 13.78 mg/g dry extract). Apigenin was detected in the inflorescence extract, reaching 3.55 ± 1.42 mg/g dry extract. The extracts did not markedly affect HaCaT viability at 15.63–500 µg/mL, while the strongest bioactivities were observed for inflorescence and maternal plant extracts. Full article

Plant regeneration demonstrates the remarkable developmental plasticity of plants, enabling tissue repair, organ formation, and adaptation to environmental challenges through cellular reprogramming and redifferentiation. This capacity underpins numerous horticultural and biotechnological applications, including grafting, micropropagation, somatic embryogenesis, organogenesis, and genetic transformation. While regeneration has traditionally been explained by the coordinated actions of auxin and cytokinin together with key developmental regulators such as WUSCHEL, BABY BOOM, and WUSCHEL-related homeobox genes, recent studies indicate that regeneration is also influenced by stress signaling, metabolic reprogramming, reactive oxygen species, and epigenetic regulation. Among these regulatory components, polyamines have emerged as important modulators of cell division, differentiation, stress responses, and morphogenic competence during in vitro regeneration. Likewise, autophagy, a conserved intracellular recycling pathway, has gained increasing attention for its role in maintaining cellular homeostasis, facilitating metabolic adaptation, and supporting developmental transitions under tissue culture conditions. This review summarizes current knowledge on the independent roles of polyamines and autophagy in plant cell reprogramming and in vitro regeneration, with particular emphasis on wound responses, somatic embryogenesis, and organogenesis. In addition, it highlights common physiological processes through which these pathways may influence regeneration and identifies the limited understanding of their potential relationship as an important direction for future research. Full article