Search Results (142)

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

This study evaluated biomass accumulation and phenolic compound production in seven Hypericum species (H. androsaemum, H. calycinum, H. hirsutum, H. kalmianum, H. olympicum, H. perforatum, and H. triquetrifolium) cultivated in vitro under varying growth regulator treatments and culture periods. Shoots were grown on Murashige and Skoog (MS) medium supplemented with benzyladenine (BA) or meta-topoline (mT) and analyzed after 40 and 60 days. MS medium supplemented with 0.2 mg/L BA was the most effective condition for promoting biomass across all species, with shoot fresh weight increasing significantly at 60 days, particularly in H. olympicum, H. perforatum, and H. triquetrifolium. High-performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS) identified 13 phenolic compounds, including flavonols, hydroxycinnamic acids, anthocyanins, phloroglucinols, and naphthodianthrones. Phenolic profiles were species-specific and influenced by culture period. H. kalmianum accumulated the highest total phenolic content (37.6 mg/g DW), while H. olympicum was the top producer of hypericin and pseudohypericin. These results highlight the crucial role of culture conditions in regulating both biomass and phytochemical production and provide a promising approach for producing bioactive metabolites in Hypericum species through in vitro systems. Full article

Light influence on shoot regeneration in Prunus salicina is a complex interaction that has been studied for the first time. Japanese plum plants were regenerated from calli and seeds of the scion cultivar ‘Victoria’. The effect of four different light spectra (white, blue, red, and mixed), along with three 6-benzyladenine (BA) concentrations (1, 1.5, and 2 mg L⁻¹), was studied in these two sources of explants. Organogenic calli were derived from the base of stem explants of the scion cultivar ‘Victoria’, whereas cotyledons and embryogenic axis slices were used as seed explants. Calli cultured with 2 mg L⁻¹ of BA and mixed light or 2.5 mg L⁻¹ of BA and control light showed the highest regeneration rates, with no significant differences compared to other treatments. Seed explants exposed to 2.5 mg L⁻¹ of BA and red light exhibited significantly higher organogenesis. In comparison, those in 1.5 mg L⁻¹ of BA with blue light or 2.5 mg L⁻¹ of BA with mixed/control light showed no regeneration. BA concentration did not have a significant effect in the induction of somatic shoots from any explant source. In contrast, a strong interaction between light and BA was noticed. This work presents a protocol that can be applied in transformation and editing research as light spectrum studies continue to advance. Full article

An efficient in vitro propagation protocol for Eulophia bicallosa was developed using asymbiotic seed germination and protocorm proliferation. The effect of light on seed germination and development was evaluated on Vacin and Went (VW) medium under five conditions: darkness, white, green, red, and blue light for 24 weeks. Blue and red light significantly accelerated seed development, allowing progression to stage 5 within 24 weeks. For protocorm proliferation, six semi-solid culture media were tested. Half-strength Murashige and Skoog (½MS) medium yielded the best results after 8 weeks, producing the highest numbers of shoots (1.0), leaves (1.1), and roots (4.2) per protocorm, with 100% survival. The effects of organic additives were also evaluated using coconut water and potato extract. A combination of 200 mL L⁻¹ coconut water and 50 g L⁻¹ potato extract enhanced shoot formation (1.7 shoots), while 150 mL L⁻¹ coconut water with 50 g L⁻¹ potato extract increased both leaf (1.9) and root (8.8) numbers. The effects of cytokinins (benzyladenine (BA), kinetin (6-furfurylaminopurine), and thidiazuron (TDZ)) and auxins (indole-3-acetic acid (IAA), α-naphthalene acetic acid (NAA), indole-3-butyric acid (IBA), and 2,4-dichlorophenoxyacetic acid (2,4-D)) were investigated using ½MS medium supplemented with each plant growth regulator individually at concentrations of 0, 0.1, 0.5, 1.0, and 2.0 mg L⁻¹. Among the cytokinins, 0.1 mg L⁻¹ BA produced the highest survival rate (96%), while 1.0 mg L⁻¹ BA induced the greatest shoot formation (93%, 2.3 shoots). Among the auxins, 0.1 mg L⁻¹ IAA resulted in the highest survival (96%), and 1.0 mg L⁻¹ IAA significantly enhanced root induction (4.2 roots per protocorm). Acclimatization in pots containing a 1:1:1 (v/v) mixture of pumice, sand, and soil resulted in 100% survival. This protocol provides a reliable and effective approach for the mass propagation and ex situ conservation of E. bicallosa. Full article

Triadica sebifera, an economically and medicinally valuable tree species native to China, was investigated for its in vitro regeneration potential using leaf explants from nodal cuttings of young stems and sprouts. This study evaluated the effects of basal media, plant growth regulators (PGRs), explant sources, and incision methods on adventitious shoot induction, supplemented by histological analysis. The highest shoot regeneration frequency (98.89%) and maximum shoot number (72) were achieved via direct organogenesis using sucker-derived nodal cuttings cultured on MS medium with 2 mg/L 6- benzyladenine (6-BA), 0.3 mg/L kinetin (KT), and 0.2 mg/L α-naphthaleneacetic acid (NAA). Under identical conditions, branch-derived explants showed lower regeneration (84.44%, 64 shoots). Transverse midvein incision proved most effective, with sucker-derived leaves exhibiting superior regeneration. Shoots elongated completely (100%) on Murashige and Skoog (MS) medium containing 0.3 mg/L 6-BA, 0.03 mg/L NAA, and activated charcoal. Rooting was optimal on MS medium with 0.3 mg/L indole-3-butyric acid (IBA), yielding a 98% acclimatization survival rate. Histological analysis revealed de novo meristem formation from parenchyma cells, confirming direct organogenesis without callus intermediation, further validating the enhanced regenerative capacity of sprout-derived explants. This efficient in vitro regeneration system provides a foundation for large-scale propagation and germplasm conservation of T. sebifera, while offering insights for woody plant regeneration studies. Full article

Turmeric (Curcuma longa L. cv. Trang 1), a high-value cultivar known for its elevated curcuminoid and volatile oil content, holds significant potential in pharmaceutical and food applications. However, its commercial propagation is constrained by low rhizome productivity and the limitations of conventional vegetative propagation. This study aimed to improve the propagation efficiency of turmeric cv. Trang 1 by developing optimized protocols for explant sterilization, shoot proliferation, root induction, and acclimatization. Sprouted rhizome buds were sterilized and cultured on a Murashige and Skoog (MS) medium supplemented with various plant growth regulators, including cytokinins (benzyladenine [BA], thidiazuron [TDZ], and meta-topolin [mT]) and auxins (indole-3-butyric acid [IBA] and 1-naphthaleneacetic acid [NAA]). The shoot induction (4.60 ± 1.47 shoots per explant) and shoot height (2.34 ± 0.61 cm) were observed on the MS medium with 3.0 mg/L BA, while the TDZ, at 0.5 mg/L, also induced a high number of shoots (5.22 ± 0.64). When using single shoots derived from bud explants, mT at 1.5 mg/L significantly enhanced the shoot formation. For the root induction, 2.0 mg/L IBA yielded the highest number of roots (7.33 ± 1.49), while NAA was less effective. The plantlets acclimatized in a 1:1 soil and peat moss mixture showed the highest survival rate (86.67%). This improved protocol enables the efficient production of turmeric plantlets, supporting commercial deployment. Full article

Rice (Oryza sativa L.) is a staple food for billions of people globally. Rice cultivar RD43 has been recognized for its health benefits but has faced declining productivity due to climate change. Plant tissue culture serves as a powerful tool for studying and improving rice cultivars, yet a standardized protocol for rice cv. RD43 is lacking. This study aims to establish an efficient plant tissue culture protocol for rice cv. RD43 by evaluating concentrations of plant growth regulators for callus induction, proliferation, and regeneration. Callus induction was most effective with 4.0 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D), while callus proliferation was effective with 2.0 mg/L of 2,4-D. Furthermore, 2.0 mg/L of 6-benzyladenine (BA) yielded the highest plant regeneration, achieving a 50% regeneration rate and producing 9.60 shoots per callus. These findings lay the groundwork for a robust tissue culture protocol for rice cv. RD43 as a means for advanced breeding studies and contributing to global food security amid climate change challenges. Full article

In recent years, there has been growing interest in the use of native ground-grown perennials in floral compositions as cut greenery. The easily available plant materials that can replace some exotic species include Hosta leaves and the leafy shoots of Polygonatum multiflorum. Their vase life should be at least as long as that of the flowers, with which they are combined. In order to prolong the vase life of cut greenery, the conditioning of cut plant material in solutions of plant hormones (GA3 and BA) and commercial conditioning substances (8HQC and Chrysal Clear 2) is most commonly performed. The aim of this study was to evaluate the effect of different conditioning solutions on vase life and parameters indicating the progression of the senescence of plant materials. Cut Hosta leaves and leafy shoots of Polygonatum multiflorum were conditioned immediately after cutting for 24 h in aqueous solutions of benzyladenine (BA) and gibberellic acid (GA₃), 8HQC standard medium with the addition of 2% sucrose and 1% Chrysal Clear 2 solution. The post-harvest storage and physiological senescence parameters of the plant materials were analyzed using the following indicators: the vase life, the relative water content (RWC), electrolyte leakage (E_L), and thiobarbituric acid reactive substance (TBARS) and pigment contents (chlorophyll a, chlorophyll b, carotenoids, and anthocyanins). Conditioning Hosta leaves in a BA solution at 100 mg L⁻¹ immediately after cutting more than doubles their post-harvest vase life. The longevity of P. multiflorum shoots can be effectively extended by storage in a BA solution of 400 mg L⁻¹, for 24 h. Both the plant materials responded to the progressive aging process with the disruption of water management, a reduction in cytoplasmic membrane integrity, and a decrease in the plant pigment content. Tissue water retention in the Hosta leaves was most favorably affected by conditioning in the GA₃ solution at a concentration of 400 mg L⁻¹. The P. multiflorum shoots responded with tissue water retention to conditioning in 1% Chrysal Clear 2 solution. The conditioning of Hosta leaves in BA solution at 400 mg L⁻¹ stabilized the cytoplasmic membranes and inhibited E_L most effectively. In P. multiflorum, the lowest E_L level was found as an effect of conditioning the shoots in GA₃ solution at 200 mg L⁻¹. The degradation of assimilation pigments was prevented by conditioning the Hosta leaves in GA₃ solution at 200 mg L⁻¹ and the P. multiflorum leafy shoots in GA₃ solution, regardless of the concentration used. Although the prolongation of the vase life of the cut leaves and the shoots by up to 30 days was achieved, along with an improvement in the appearance of the plant materials, it was not possible to identify a single conditioner that had a positive effect on all the parameters studied. Full article

Ballota acetabulosa (L.) Benth. (syn. Pseudodictamnus acetabulosus (L.) Salmaki and Siadati), f. Lamiaceae, the Greek horehound, is a compact evergreen small shrub native to Greece, with hairy grey-green leaves, that bears small pink-purple flowers with green conical calyxes along its erect stems in late spring. The species stands out for its high resistance in xerothermic conditions and therefore it is advisable to promote its use in xeriscaping. The aim of this study was to develop an efficient protocol for in vitro propagation of B. acetabulosa for introduction into the horticultural and pharmaceutical industries. Shoot tip and single node explants derived from in vitro seedlings were cultured on MS medium with various cytokinin types and concentrations. Explants responded at almost 100% to produce high number of shoots on a medium with 1.0 mg L⁻¹ zeatin or 6-benzyladenine. However, there was intense hyperhydricity in the cultures, which was addressed in further experiments by increasing agar concentration from 8 to 12 g L⁻¹, preserving high multiplication indices (92% response, 10.2 shoots per explant). Microcuttings with 2–3 visible nodes, either from the apical part, including the apical meristem, or from the basal part of microshoots, as well as microshoot clusters, rooted 100% on full- or half-strength MS medium, respectively, regardless of the addition of indole-3-butyric acid (ΙΒA, 0.5–4.0 mg L⁻¹) in the rooting medium. However, middle level concentrations of IBA increased the number and length of roots produced, while the higher its concentration, the more and longer axillary shoots developed in the microcuttings during the rooting period. The acclimatization of all plantlets was completely successful (100%) in ex vitro conditions on peat/perlite substrate (1:1, v/v). Thus, efficient methods of producing propagation material to promote Ballota acetabulosa as a horticultural and medicinal plant were developed. In particular, rooting of microshoot clusters or microcuttings without the shoot tip, in the presence of 1.0 mg L⁻¹ IBA, leads to a plant of suitable shape for the floricultural market, without the need for further manipulation (pruning) in the nursery. Full article

The success of double cropping in Vitis vinifera L. cultivated in temperate climates relies on bud forcing efficiency, which requires the prompt unlocking of apical dormant buds with sufficient fruitfulness. Chemical dormancy-breaking strategies need to be tested to enhance dormant bud forcing in summer pruning, as hydrogen cyanamide, the most used agent, could damage green organs. This study tested whether foliar applications of cytokinins and auxins could modulate dormancy release, potentially affecting bud forcing dynamics and shoot fruitfulness. The forcing treatments involved trimming primary shoots at the eighth node, removing lateral shoots, and retaining the main leaves and inflorescences. Five treatments were investigated: unforced control, control + 6-Benzyladenine application, forcing (FR), forcing + 6-Benzyladenine application (FBA), and forcing + Naphthaleneacetic acid application (FNAA). Phenological evolution, vegetative and productive parameters, and physiological characteristics have been assessed. Results showed that among the forcing treatments, FBA showed the highest forced/primary shoots ratio (106%), followed by FR (94%) and FNAA (21%). Primary yields were similar across treatments (2.74 kg), but total yield was highest in FBA (4.78 kg, including 2.02 kg from forced grapes), followed by FR (3.62 kg, with 1.09 kg forced). FNAA yielded no forced crop. During forced grapes maturation, photosynthesis rates were higher in forced leaves (11.1 μmol m⁻² s⁻¹, as FR and FBA average) than primary leaves (−32%). Forced grapes ripened 47 days later and achieved higher sugar content (21.7 °Brix) and titratable acidity (10.6 g/L) than primary grapes. The findings suggest cytokinins application enhances bud forcing, supporting the feasibility of double cropping, while auxins limited it. Full article

Lettuce genetic transformation is genotype-dependent. In the present study, we have successfully developed an optimized Agrobacterium-mediated transformation protocol for elite lettuce cultivars, which belong to the romaine, leaf, and butterhead cultivar types. We optimized the type and concentration of plant growth regulators (PGRs) and selection antibiotics and found that the use of 1-naphthaleneacetic acid (NAA; 0.10 mg/L) and 6-benzyladenine (BA; 0.25 mg/L) as plant growth regulators, the use of hygromycin (15 mg/L) for transgenic plant selection, and the use of cotyledons and the first true leaf as explants efficiently yielded transformed plants for seven out of the eleven tested cultivars, achieving a 24.3–100% transformation efficiency. These seven cultivars include two romaine-type cultivars, three leaf-type cultivars, and two butterhead-type cultivars, and mark the first successful genetic transformation of the romaine cultivars ‘Kahu’ and ‘Rosalita’, the leaf cultivars ‘Red Sails’ and ‘Royal Oak Leaf’, and the butterhead cultivar ‘Lollo Biondo’. We also observed that substituting hygromycin selection with kanamycin selection (40 mg/L) resulted in a 64.3% transformation efficiency in the butterhead-type ‘Mariska’, one of the remaining four cultivars. Our newly optimized protocols are applicable in elite lettuce cultivars for Agrobacterium-mediated genetic transformation and regeneration, enabling hygromycin or kanamycin selection. Full article

Saffron (Crocus sativus L.), a perennial geophyte from the Iridaceae family, blooms in autumn and thrives in Mediterranean-like climates. It is highly valued for its therapeutic and commercial uses. While saffron cultivation generally requires minimal water, insufficient irrigation can negatively impact its yield. Although numerous studies have explored the detrimental impact of drought on saffron under field conditions, its impact in vitro remains largely unexplored. The present study aims to investigate the effects of polyethylene glycol (PEG) 6000 at concentrations of 0%, 5%, and 10% in inducing drought stress on saffron shoots under controlled conditions. The research focuses on evaluating morphological, physiological, and biochemical changes and analyzing the expression of drought-responsive genes. Shoot establishment was carried out on Murashige and Skoog (MS) medium supplemented with 6 mg/L 6-benzyladenine (BAP) and 1 mg/L naphthaleneacetic acid (NAA), while PEG 6000 was used to induce drought stress. Various morphological, biochemical, and molecular parameters were assessed 30 days after stress induction. Increasing PEG concentrations in the medium significantly reduced shoot regeneration, leading to increased apical tissue browning. Significant chlorophyll and carotenoid level changes were observed in shoots exposed to higher PEG concentrations. PEG-induced drought led to decreased plant growth and biomass and lowered relative water content of leaves. Lipid peroxidation, membrane damage, and H₂O₂ content increased, indicating heightened stress levels. Proline concentration significantly increased in plants subjected to 5% and 10% PEG compared to controls. Non-enzymatic antioxidant activity (phenolics, flavonoids, % inhibition, total reducing power, and total antioxidant activity) also increased with the severity of stress. In contrast, a decrease in the activity of superoxide dismutase (SOD) and peroxidase was observed in PEG-treated shoots. Significant changes in the expression of drought-related genes, such as DREB1, DREB2, AREB1, DHN1 (Dehydrin), and SnRK2, were observed in shoots exposed to 5% and 10% PEG. In conclusion, the study highlights that PEG, as an inducer of drought stress, negatively impacts saffron’s growth and physiological responses under in vitro conditions. It also triggers significant changes in biochemical and molecular mechanisms, indicating the plant’s susceptibility to water scarcity. Full article

Anthocyanins are important flavonoid compounds in plants that are associated with the color formation and antioxidant activity of flowers, fruits, and other organs. Ultraviolet B radiation (UV-B) is one of the key environmental factors that influence anthocyanin accumulation in plants and HY5 is involved in plant photomorphogenesis. However, the molecular mechanism of the signal network of UV-B regulating anthocyanin biosynthesis in capsicum via HY5 remains unclear. In this study, we identified the transcription factor CaHY5, which mediates UV-B signaling, and demonstrated its regulatory role in anthocyanin biosynthesis in purple pepper (Capsicum annuum L.). The results showed that there were photoresponsive and hormone-responsive elements on the CaHY5 promoter that responded to UV-B, indoleacetic acid, salicylic acid, 6-benzyladenine, abscisic acid, and melatonin treatments. UV-B treatment induced the expression of CaHY5 and anthocyanin structural genes. CaHY5 gene-silenced positive plants showed different degrees of the yellowing phenomenon, which affected the expression of the anthocyanin biosynthesis structural gene. The expression levels of anthocyanin biosynthesis-related genes in CaHY5-silenced positive plants increased considerably. This study provides insights into the role of CaHY5 in UV-B-induced anthocyanin biosynthesis in purple pepper. Full article

Quercus suber L. (Q. suber) is an evergreen tree species known for producing high-quality cork. Traditional seed propagation of Q. suber has low viability and is time-consuming. Therefore, we used young stem segments of 2~3-year-old seedlings as explants, and optimized protocols for tissue culture and rapid micropropagation of Q. suber. The best disinfection method was 0.10% HgCl₂ (v/v) for 5 min. 0.50 g·L⁻¹ Poly Vinyl Pyrrolidone (PVP) is the best anti-browning agent with a significant reduction in browning by nearly 1.76-fold (58.89% → 33.33%). Woody Plant Medium supplemented with micronutrients and vitamins from Murashige and Skoog Medium (WPMS) was found to be the most suitable for shoot formation. The optimal hormone ratio for development of shoots from axillary buds was 0.60 mg·L⁻¹ 6-benzyladenine (6-BA). Among the cytokinins tested, 0.50 mg·L⁻¹ 6-BA was the most suitable for development of shoots from axillary buds. In additon, the highest percentage of rooting explants (66.67%) and rooting number (3.03) was obtained on WPM basal medium supplemented 0.20 mg·L⁻¹ IBA and 0.20 mg·L⁻¹ NAA. In summary, we have established a set of protocols for tissue culture and rapid micropropagation of Q. suber. These findings lay the foundation for rapid micropropagation and genetic improvement. Full article

Human skin fibroblasts are an excellent in vitro model for tracking the processes occurring in human skin and studying the potential impact of various biologically active substances on these processes. Two plant hormones, which are included in the cytokinins group—kinetin (K) and N-6-benzyladenine (BA)—have a positive effect on human skin. Therefore, an attempt was made to examine the effect they have on key skin functions, cell proliferation, and migration, as well as collagen synthesis in them. The effect of phytohormones was studied at selected concentrations for kinetin—10 μM and 1 μM—and for N-6-benzyladenine—1 μM and 0.1 μM. A wound-healing assay was used in order to analyze cell migration and proliferation. The content of total protein and collagen in cells and culture medium was determined. The obtained results confirm that the studied compounds induce cell migration and proliferation, as well as collagen biosynthesis. The positive effect of kinetin and N-6-benzyladenine on fibroblast metabolism that we have demonstrated allows us to indicate them as compounds with potentially therapeutic properties. Therefore, we conclude that they should be subjected to further molecular and in vivo studies focusing on pathologies connected with skin diseases and aging. Full article