Search Results (133)

Rosa canina L. is a medicinal and nutritionally valuable species with increasing industrial demand, yet its conventional propagation is limited by low rooting capacity and high genetic heterogeneity. In this study, a complete and reproducible in vitro micropropagation protocol was established, from explant introduction to plantlet acclimatization. Axillary buds were disinfected and introduced into Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (BAP). Shoot multiplication was achieved using sequential cytokinin treatments, and shoot elongation was promoted by adding liquid MS medium containing activated charcoal (AC). The highest and fastest root induction percentage (up to 75%) was obtained on WPM with 2 mg·L⁻¹ IBA and under a 16 h light/8 h dark photoperiod. Light promoted adventitious root formation depending on the nutrient formulation. Thereafter, shoots developed well-structured root systems in vitro, and plantlets fully survived to ex vitro acclimatization. This protocol provides an efficient platform for the large-scale propagation of R. canina and demonstrates that its auxin-driven adventitious rooting is strongly conditioned by the interaction between basal medium composition and photoperiod. Full article

Shoot tip cryopreservation is essential for the long-term conservation of plant genetic resources. It provides the only reliable method for establishing a long-term, readily available gene pool of clonally propagated crops and elite in vitro clones used in the pharmaceutical, food, and cosmetic industries. Still, its success is often limited by the inherent sensitivity of many species to the osmotic and chemical stresses imposed by concentrated cryoprotectant (vitrification) solutions and severe dehydration. The optimization of modern cryopreservation protocols primarily focuses on modifying shoot tip preculture, cryoprotectant treatments, or regrowth conditions, while frequently overlooking donor plant preconditioning or relegating it to a secondary role. However, the physiological state of in vitro plants from which apical or axillary shoot tips are extracted may hold the key to successful post-cryopreservation recovery, especially in cryo-sensitive taxa. This review revisits the critical role of donor plant vigor and induced stress tolerance in the cryopreservation of clonal crops by systematically evaluating preconditioning strategies, including cold acclimation, sucrose pretreatment, and the use of growth regulators and signaling molecules such as abscisic, jasmonic, and salicylic acids, involved in stress signaling and tolerance development. The beneficial physiological changes induced by donor plant pretreatment, such as reduced freezable water content and the accumulation of protective compounds, are discussed in the context of contemporary cryopreservation methods. The effects of culture conditions, including the roles of ammonium and nitrates, light quality, culture density and aeration, medium strength, culture age, and subculture duration, are also considered. We analyze how different treatments of in vitro donor plants improve shoot tip tolerance to osmotic and/or chemical toxicity imposed by specific cryopreservation methods to support a material-centered selection of a cryopreservation procedure. Future directions and potential approaches for integrating target donor plant preconditioning into modern cryopreservation protocols for shoot tips, particularly in stress-sensitive species, are discussed. Full article

The provincial-level registered superior cultivar Camellia chekiangoleosa ‘Ganhongyou 1’ boasts superior economic traits coupled with significant ornamental value, driving demand for an efficient propagation system. Consequently, this study aimed to develop a rapid micropropagation protocol by investigating culture conditions using semi-woody nodal segments with axillary buds as explants on Hyponex basal medium supplemented with varying combinations of plant growth regulators. Contamination was effectively minimized to 18% by a combined approach of surface sterilization (75% ethanol, 0.1% HgCl₂, and 20% NaClO) and incorporating 1 mL/L bactericide into the induction medium. For bud induction, the optimal medium was 2 g/L Hyponex supplemented with 1.0 mg/L 6-benzylaminopurine (6-BA) and 0.2 mg/L indole-3-acetic acid (IAA), achieving an 86.67% induction rate. The best proliferation was achieved on the medium containing 2 g/L Hyponex, 1.0 mg/L 6-BA, 0.15 mg/L 3-indolebutyric acid (IBA), and 0.5 mg/L gibberellic acid (GA₃), yielding a proliferation coefficient of 6.53. A combined strategy, integrating in vitro pre-culture with ex vitro treatment, proved most effective for rooting and acclimatization: shoots were first pre-cultured for 20 days on 1/2 strength Hyponex medium supplemented with 0.5 mg/L 1-naphthaleneacetic acid (NAA) and 2.0 mg/L IBA, followed by ex vitro base treatment with 1.0 g/L ABT (a rooting powder complex) solution before transplantation into seedling bags. This approach resulted in an 88% survival rate. Furthermore, anatomical analysis revealed the origin of adventitious root primordia from phloem parenchyma cells, thereby confirming a phloem-rooting pattern for this species. In conclusion, this study establishes a practical and efficient micropropagation protocol for ‘Ganhongyou 1’, providing a reliable technical foundation for its commercial-scale seedling production. Full article

As sessile organisms, plants adapt to their environments through shoot branching, a key determinant of plant architecture. However, the regulatory mechanisms governing this trait in cucumber remain incompletely understood. Although certain WRKY transcription factors have been implicated in branching regulation in other species, whether they are involved in cucumber branching has not yet been reported. In this study, we identified a transcription factor, CsWRKY50, whose expression positively correlates with branching in cucumber. The transcript level of CsWRKY50 was markedly elevated in the multi-branching mutant nwd and in high-branching cucumber varieties. Notably, CsWRKY50 showed the highest expression in axillary meristems compared to other tissues. Heterologous overexpression of CsWRKY50 in Arabidopsis significantly increased branch number and altered the transcriptional levels of several branching-related genes. Yeast two-hybrid assays confirmed that CsWRKY50 interacts with CsRAX5 and a truncated form of CsMYB84. The additive branching phenotype observed in the CsWRKY50-overexpressing Atbrc1 mutant indicates that CsWRKY50 may function independently of BRC1. Notably, RAX genes were up-regulated under these conditions. This work provides novel genetic resources and a theoretical foundation for improving plant architecture in cucumber cultivation. Full article

The excessive and random production of summer shoots poses significant challenges to pest and disease management and the improvement of fruit quality in citrus orchards. Although heavy fruit load has been observed to reduce summer shoot numbers, the mechanism is not well understood. This study combined a field investigation with a de-fruiting experiment to demonstrate that significant negative correlation exists between fruit load and summer shoot numbers in citrus orchard. Metabolomic analysis further indicated that fruits at the cell expansion stage function as dominant carbohydrate sinks, attracting more soluble sugars. De-fruiting significantly elevated sugar content and upregulated the transcript levels of sink strength-related genes (Sucrose synthase, CsSUS4/5/6) by more than 3.0-fold in the axillary buds. Additionally, exogenous application of sugar-related DAMs (differentially accumulated metabolites), such as sucrose, significantly promoted axillary bud outgrowth. Taken together, our findings confirm that heavy fruit load suppresses shoot branching, primarily through competing for soluble sugars. This provides a physiological basis for managing summer shoots by regulating fruit load, offering a practical strategy to enhance citrus orchard management and the effectiveness of pest and disease control programs. Full article

Axillary buds are key organs that determine shoot branching and aerial architecture in plants and critically influence crop growth and productivity. Understanding the molecular mechanisms underlying the transition from dormancy to bud activation is a central question in plant developmental regulation. Although previous studies have revealed post-release developmental processes, the early regulatory network that triggers dormancy release remains unclear. In this study, we used tobacco (Nicotiana tabacum) as a model and focused on transcriptomic changes of regulatory factors in axillary buds within 36 h after decapitation. Then, we systematically analyzed key molecular events that induce dormancy release. The results revealed the involvement of diverse signals in decapitation-induced bud activation, including key plant hormones like auxin, cytokinin, and gibberellin; as well as external cues such as sugar, nitrogen, and light. Significant changes occurred as early as 0.5 to 1 h after decapitation. Among these, auxin and sugar signaling played central roles in initiating dormancy release. In addition, various signaling factors exhibited coordinated regulatory effects during the continued development of activated buds. Functional validation further demonstrated that EXB1 and STM, two key regulators of axillary bud initiation, participated in the subsequent stages of branch development. In conclusion, our study reveals that decapitation-induced dormancy release of axillary buds occurs at a very early stage (0.5–1 h). This rapid response is driven by a complex regulatory network involving multiple hormones and metabolic signals. These findings provide new molecular insights into the dynamic regulatory balance of axillary bud development. They also establish a theoretical basis and strategic reference for trait regulation and modular breeding design. Full article

The present study investigated the effects of copper oxide nanoparticles (CuO NPs) at concentrations of 0, 5, 10, 20, and 40 mg/L on micropropagation and the accumulation of lipophilic metabolites in Ajuga multiflora, a medicinally valuable ornamental species. The highest number of adventitious shoots (29.4 shoots per explant) was obtained on the shoot induction medium with 5 mg/L CuO NPs. Shoot production gradually decreased at higher CuO NPs concentrations, falling to just 1.1 shoots per explant at 40 mg/L CuO NPs. A similar pattern was seen in axillary shoot multiplication (22.4 shoots per explant at 5 mg/L CuO NPs). However, the maximum shoot fresh weight (0.269 g) was reached on the shoot multiplication medium containing 10 mg/L CuO NPs. Root induction was most effective at 5–10 mg/L CuO NPs, while higher concentrations (20 or 40 mg/L CuO NPs) suppressed or inhibited root formation and altered plantlet morphology. Notably, this study is among the first to assess CuO NPs’ effects across multiple regeneration stages rather than focusing on just one morphogenic event. This emphasizes the importance of optimizing the dose not only for initial shoot induction but also for later multiplication and rooting, ensuring effective micropropagation. Metabolite analysis showed that both the type of organ (microshoots vs. leaves) and CuO NPs concentration significantly affected the levels of α-tocopherol, carotenoids, sterols, and fatty acids. Leaves had higher amounts of α-tocopherol and total carotenoids compared to microshoots. The phytosterol levels also varied, with leaves containing more 22-dehydroclerosterol and total phytosterols, while microshoots had more clerosterol. Treatment with 5 mg/L CuO NPs increased phytosterol accumulation in both organs. CuO NPs significantly influenced the fatty acid profiles. In microshoots, total polyunsaturated fatty acids (PUFAs) increased and total saturated fatty acids (SFAs) decreased with higher CuO NPs levels. Conversely, in leaves, higher CuO NPs concentrations led to increased SFAs and decreased PUFAs, along with a significant rise in the omega-6 (n-6)/n-3 PUFAs ratio. These findings suggest that controlled application of CuO NPs can serve as an elicitor to boost phytochemical production during micropropagation. Full article

Shoot cultures of Nepeta curviflora were used to test the effect of 6-benzylaminopurine (BAP) and riboside 6-benzylaminopurine (r-BAP) on the growth and production of phenolic compounds. The best multiplication was achieved on agar Murashige and Skoog medium (MS) with r-BAP (1.5 mg/L), where 74% of explants produced about eight axillary shoots. The fresh weight (FW) was about 0.6 g/tube (24 g/L) and the dry weight (DW) was about 0.04 g/tube (2 g/L). To scale up the culture, the shoot culture was grown for the first time in a nutrient sprinkle bioreactor. After 4 weeks of culture, the multiplication rate (8.13) was higher than that observed in glass tubes (8.03). The fresh biomass was 113.2 g/bioreactor (75.5 g/L) and the dry mass was 14 g/bioreactor (9.3 g/L). Extracts from obtained plant material were analyzed by the UPLC/DAD/qTOF-MS technique. A total of 32 phenolic compounds were identified and quantified. The total content of compounds ranged from 600 to 1400 mg/100 g of dry weight (DW), depending on the culture conditions. In the profile of shoot cultures, rosmarinic acid was dominant, whereas prolithospermic acid was mostly noted in extract from aerial parts of the plant obtained from the field. Full article

Background/Objectives: This study aims to screen the extracts of tomato plant waste (aerial parts—mixture of leaves, stems, and bunches resulting from tomato crop maintenance, and axillary shoots—resulting from pruning practices) and evaluate their antifungal, prebiotic, and cytotoxic effects. Methods: A phytochemical profiling was performed to analyze volatile and semi-volatile compounds by GC-MS, functional groups by FTIR, soluble sugars by HPLC-RI, and glycoalkaloids by LC-MS/MS. Tomato plant waste extracts were further tested in vitro, and their biological effects were assessed with probiotic microorganisms (Enterococcus faecium ATCC 19434, Enterococcus faecium VL43, Lactobacillus plantarum ATCC 8014, and Lactobacillus plantarum GM3) to determine their prebiotic-like properties, particularly after demonstrating strong antifungal activity against several Candida species, such as Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019, Candida glabrata ATCC 64677, and Candida auris 6328. The extracts were also evaluated for the cytotoxic effect against HEP-G2, HeLa, and HT-29 cell lines, while cytotoxicity assays confirmed no significant effects on the normal HEK-293 cell line compared to the control. Results: The in vitro antimicrobial activity and prebiotic-like substrate assay proved the difference between extract effects against Candida species (C. glabrata—MIC 125 µg/mL) and, respectively, the influence on Lactobacillus strains growth (up to a 1.6-fold increase in OD₆₀₀). Furthermore, they exhibited selective cytotoxicity against HEP-G2, HeLa, and HT-29 cancer cell lines, while showing no significant toxicity on normal HEK-293 cells. Conclusions: Overall, this research highlights tomato axillary shoots as a sustainable source of bioactive compounds, with potential applications in developing natural, plant-based prebiotic products that exhibit antifungal and antitumor activity. This research focuses on developing natural, plant-based prebiotic products with antifungal and cytotoxic effects. Full article

In Lolium perenne, a novel growth habit mutant, named VIROIZ, was recovered following colchicine treatment, and it was confirmed to maintain the diploid chromosome number (2n = 2x = 14). The mutation affected the stem morphology by inducing prolific axillary shoot formation at nodal zones, resulting in a spreading growth habit that can extend to ~70 cm in width. Inheritance analysis based on single-plant evaluations in crosses with wild-type plants (F₁, n = 285; F₂, n = 380) and in selfed progeny (S₁, n = 255) consistently showed ~40% expression of the spreading phenotype, deviating from classical Mendelian ratios and indicating complex genetic control. Phenotypic selection further distinguished divergent classes: positively selected lines (C1⁺) averaged 3.90 axillary tillers per stem, whereas negatively selected lines (C1⁻) averaged only 0.22. Partial sequencing of 11 candidate genes implicated in shoot architecture, covering 40–90% of full-length DNA, did not provide a conclusive explanation for the altered stem growth. Notably, a single point mutation was observed in CRT3 (an endoplasmic reticulum chaperone that interacts with brassinosteroid signaling) highlighting it as a primary target for future studies. Cytological analysis of meiosis in F₁ hybrids between VIROIZ and wild-type plants revealed irregular chromosome pairing with persistent univalents (2–4 per cell), supporting the presence of structural chromosomal rearrangements that may disrupt gene organization and function in VIROIZ. The non-Mendelian segregation of the spreading phenotype, together with the observed meiotic irregularities, suggests that the mutation affects regulatory genes responsive to hormonal signals controlling axillary meristem initiation. The mutant represents a valuable resource for turf-type L. perenne breeding and for studying hormonal regulation of shoot morphogenesis in Poaceae. Full article

Camptotheca acuminata produces valuable camptothecin, a potent anticancer agent. To overcome the limitations of wild resources, we developed efficient in vitro regeneration and camptothecin production systems. Key findings include: Optimal sterilization of plant material was achieved using Plant Preservative Mixture (12 min). Axillary shoot induction was most effective on MS medium with 2.5 mg/L 6-BA and 0.25 mg/L NAA, while adventitious shoot regeneration showed a preference for 1 mg/L 6-BA and 0.1 mg/L NAA. Synchronous induction reached its peak at 83.45% using MS medium with 0.5 mg/L 6-BA, 0.05 mg/L NAA, and 0.5 mg/L GA₃. Shoot elongation benefited from 5 mg/L phloroglucinol and 20 mg/L CaCl₂. For biomass production, 2/3 MS macroelements yielded maximum adventitious shoot biomass (50.52 mg). Rooting reached 100% efficiency on 1/2 MS medium containing 1 mg/L IBA, 0.5 mg/L NAA, 5 mg/L phloroglucinol, and 2 g/L AC, averaging 10.50 roots per shoot. The four-stage camptothecin enrichment system produced shoots containing 795.10 µg/g DW camptothecin—fivefold higher than natural leaves. This breakthrough establishes: (1) the first in vitro camptothecin enrichment platform; (2) a sustainable alternative to wild harvesting; (3) a novel circular production model for endangered medicinal plants. The optimized protocols address the challenges of camptothecin supply while demonstrating remarkable productivity enhancements through controlled in vitro culture systems. Full article

This study established an efficient in vitro regeneration system using stem nodes from root collar suckers as explants. Subsequently, regenerated shoots were used to establish an in vitro medicinal production protocol that achieved ginkgolic acid production. The self-developed Ginkgo biloba medium (GBM), first reported in this study, was pivotal to system establishment. The plantlet propagation system showed that the bases of stem nodes dipped in GBM with 2 mg·L⁻¹ 6-benzyladenine (BA) and 0.2 mg·L⁻¹ 1-naphthaleneacetic acid (NAA) achieved near-complete axillary bud induction (99.56%). Adventitious shoot induction reached 82.22% (3.5 shoots/explant) using GBM with 0.2 mg·L⁻¹ BA, 0.02 mg·L⁻¹ kinetin (Kin) and 0.2 g·L⁻¹ proline (Pro). Maximum adventitious shoot elongation (92.22%, average 3.35 cm) was observed on GBM containing 0.1 mg·L⁻¹ zeatin (ZT) and 0.01 mg·L⁻¹ BA. After 3-week preculture with 15 mg·L⁻¹ phloroglucinol (PG), treatment with 0.6 mg·L⁻¹ indole-3-butyric acid (IBA) and 0.2% activated carbon (AC) yielded 96.67% rooting (6.19 roots/explant) and 85% acclimatization survival. For medicinal resource production, bud cluster induction at 94.44% (20.89 buds/explant) on GBM with 1 mg·L⁻¹ BA, 0.03 mg·L⁻¹ Kin, and 0.2 g·L⁻¹ Pro. Leaf organs in GBM with 0.3 mg·L⁻¹ BA, 0.01 mg·L⁻¹ Kin, 0.01 mg·L⁻¹ IBA, 0.3 g·L⁻¹ Pro, and 0.01 mg·L⁻¹ glutamine (Gln) accumulated 20.64 g fresh weight and 41.910 mg·g⁻¹ DW ginkgolic acids, representing a 4.93-fold increase over mother plants. This system enables large-scale Ginkgo biloba L. propagation and provides an in vitro strategy for producing medicinal compounds in endangered plants. Full article

Tomato aerial parts and axillary shoots represent underutilized agricultural residues with promising phytochemical potential. Despite the recognized antioxidant capacity of rutin, current literature lacks optimized, comparative studies on its extraction from distinct tomato vegetative components. This study aimed to maximize the recovery of rutin and other bioactive compounds from tomato plant biomass using green extraction techniques—microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE)—optimized through Box–Behnken design (BBD) and Response Surface Methodology (RSM). The extraction process was optimized for three key variables: temperature, solvent concentration, and plant-to-solvent ratio. Four main responses were evaluated: total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity (DPPH), and rutin concentration. The highest rutin content (8614.23 mg/kg) was obtained in extracts from axillary shoots using MAE. Overall, MAE proved more efficient in recovering both primary and secondary metabolites from axillary shoots, while UAE favored the extraction of certain micronutrients and specific amino acids. Cascade extraction further improved the recovery of key compounds such as vitamin E and quinic acid. The comparative profiling of extracts revealed significant phytochemical differences between tomato aerial parts and axillary shoots, addressing a gap in the literature and underscoring the importance of optimized extraction strategies. These findings highlight tomato plant waste as a valuable source of antioxidant compounds and set the stage for future investigations into their biological activities. Full article

Agave species are plants with great economic value and multiple possibilities of use as ornamentals, medicinal plants, and fibers, as well as being significant sources of bioethanol. However, their long life cycles hinder their conventional breeding. Therefore, biotechnology tools are the most effective means for clonal propagation and genetic improvement. In vitro micropropagation of A. sisalana via axillary shoot proliferation from bulbil explants was attained using Murashige and Skoog medium (MS) supplemented with cytokinins (CKs), such as 6-benzyladenine (BA), kinetin (KIN), or thidiazuron (TDZ). The optimum significant shoot proliferation (14.67 shoots/explant) was achieved on 1.0 mg L⁻¹ TDZ. The carry-over effect of CKs on subsequent rooting could be detected. Control and KIN treatments could enhance the rooting of shoots on shoot proliferation media. The regenerated plantlets were acclimatized directly with 100% survival. To mitigate this carry-over effect, that causes hindering further root growth and development, and promote healthy growth of roots, subculturing shoots onto a CK-free medium is a recommended practice. The shoots induced on all BA treatments, and TDZ at 0.5 and 1.0 mg L⁻¹ could be rooted after two subcultures on CK-free medium, then they were acclimatized with 100% survival. However, the higher concentrations of TDZ inhibited in vitro rooting even after two subcultures on CK-free medium, and the acclimatization percentage was reduced by increasing the TDZ concentration recorded from 10 to 0%. Full article

Adult trees of pedunculate oak (Quercus robur L.) are recalcitrant to vegetative propagation. In this study, we investigated the micropropagation of five oak genotypes corresponding to trees aged 60–800 years in a liquid medium. We used commercial RITA bioreactors to study the influence of the explant type, the culture medium, shoot support and number of immersions. Variables evaluated included the number of normal and hyperhydric shoots, shoot length, multiplication coefficient and number of rootable shoots per explant. All genotypes could be cultured in temporary immersion. Basal stem sections attached to callus grew better than apical sections and developed less hyperhydricity. For long-term cultivation, Gresshoff and Doy medium was the best of the three media evaluated. All genotypes produced vigorous shoots suitable for rooting and acclimation. This is the first protocol to proliferate adult oak trees in bioreactors, representing significant progress towards large-scale propagation of this and other related species. Full article