61 research outputs found

    Blue led light promotes somatic embryogenesis from the lateral roots sections of spinach (Spinacia oleracea L)

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    Light and gibberellins (GAs) are essential for the induction of somatic embryogenesis in spinach. In the present study, the influence of light of different spectral qualities on the induction of somatic embryogenesis from the apical root sections of spinach seedlings was tested. The explants grown under blue light (B, emission maximum at 460 nm), provided by Light-emitting diodes (LED), exhibited the highest regeneration frequency (57.8%±0.36) and the mean somatic embryo (SE) number per explant (5.02±0.04) for eight weeks of cultivation on SE-induction medium supplemented containing 20 μM α-naphthaleneacetic acid and 5 μM GA3. The explants cultivated under white (W, 300-720 nm) LED or light provided by fluorescent lamps (FL, 380-680) produced a two times lower number of SEs per explant, while the explants grown under red (R, 630 nm) LED light or in darkness (D) failed to regenerate SEs. Considering that light greatly affects the level of GAs in plant tissues, and GAs are indispensable for SE induction in spinach, the expression profiles of genes encoding the key enzymes that catalyze the final steps of bioactive GA biosynthesis (GA20-oxidase and GA3-oxidase) and inactivation (GA2-oxidase) were tested in the explants grown under B, W or FL light. Surprisingly, no significant differences in the expression levels of these genes were observed among the treatments during of SE induction, indicating that light triggers SE induction by other mechanism, not including alterations in the expression of the aforementioned genes. Further research is needed for better understanding of the mechanism of SE induction by light

    Gentianella lutescens subsp. carpatica J. Holub.: Shoot Propagation In Vitro and Effect of Sucrose and Elicitors on Xanthones Production

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    In vitro shoot culture of the endangered medicinal plant Gentianella lutescens was established from epicotyl explants cultured on MS basal medium with 0.2 mg L−1 6-benzylaminopurine (BA) and evaluated for xanthones content for the first time. Five shoot lines were obtained and no significant variations in multiplication rate, shoot elongation, and xanthones profile were found among them. The highest rooting rate (33.3%) was achieved by shoots treated for 2 days with 5 mg L−1 indole-3-butyric acid (IBA) followed by cultivation in liquid PGR-free ½ MS medium for 60 days. HPLC analysis revealed the lower content of xanthones—mangiferin, bellidifolin, demethylbellidifolin, demethylbellidifolin-8-O-glucoside and bellidifolin-8-O-glucoside—in in vitro cultured shoots compared to wild growing plants. The increasing concentration of sucrose, sorbitol and abiotic elicitors salicylic acid (SA), jasmonic acid (JA) and methyl jasmonate (MeJA) altered shoot growth and xanthone production. Sucrose and sorbitol applied at the highest concentration of 233.6 mM increased dry matter percentage, while SA at 100 μM promoted shoot growth 2-fold. The increased sucrose concentration enhanced accumulation of xanthones in shoot cultures 2–3-fold compared to the control shoots. Elicitors at 100–300 μM increased the accumulation of mangiferin, demethylbellidifolin-8-O-glucoside, and bellidifolin-8-O-glucoside almost equally, while MeJA at the highest concentration of 500 μM enhanced amount of aglycones demethylbellidifolin and bellidifolin 7-fold compared to the control. The obtained results facilitate conservation of G. lutescens and pave the way for further research on large-scale shoot propagation and production of pharmacologically active xanthones

    Xanthones Production in Gentiana dinarica Beck Hairy Root Cultures Grown in Simple Bioreactors

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    The hairy root clones of Gentiana dinarica cl-B, cl-D, cl-3, and cl-14 were cultivated in parallel in diverse simple bioreactors, including temporary immersion systems RITA® (TIS RITA®), bubble column bioreactors (BCB), and Erlenmeyer flasks (EF), and evaluated for biomass production and xanthone content. The obtained results showed that TIS RITA® and BCB containing ½ MS medium with 4% sucrose provided equally good growth conditions in which the majority of the clones displayed the higher percentage of dry matter (DM%), and xanthones norswertianin-1-O-primeveroside (nor-1-O-prim) and norswertianin production than those cultivated in EF. Thin and well branched hairy root clone cl-B grown in BCB for 7 weeks was superior regarding all growth parameters tested, including growth index (19.97), dry weight (2.88 g), and DM% (25.70%) compared to all other clones. Cl-B cultured in TIS RITA® contained the highest amount of nor-1-O-prim (56.82 mg per vessel). In BCB with constant aeration, cl-B accumulated the highest norswertianin content reaching 18.08 mg/vessel. The optimized conditions for cultivation of selected G. dinarica hairy root clones in highly aerated TIS RITA® and BCB systems contribute to the development of bioreactor technology designed for the large scale commercial production of xanthones nor-1-O-prim and norswertianin

    Fingerprinting of the antioxidant status in Alyssum markgrafii shoots during nickel hyperaccumulation in vitro

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    This study investigated the role of antioxidant system of Alyssum markgrafii, during long-term exposure to 0.5 or 1 mM NiCl2 × 6H2O in vitro. Applied methodology included sample preparation protocol which reduces oxidation of key metabolites along with novel luminescent method and well-established photometric procedures. During 5-week treatments, plants accumulated 1121 and 2470 ppm of Ni2+ respectively, followed by severe growth retardation, chlorophyll degradation and peroxidation of lipids. These effects were more pronounced after 1 mM Ni2+ treatment and additionally accompanied by increased water loss. Activities of luminol-converting peroxidases and glutathione reductase upon 0.5 mM treatment were increased while catalase and superoxide dismutase were diminished. The fact that these two groups of enzymes run in antiparallel might suggest functional redistribution between antioxidant enzymes rather than orchestrated action to prevent oxidative damage. Total antioxidant capacity (TAC) was also increased after 0.5 mM treatment which coincided with increased GR activity and elevated glutathione content indicating this low molecular weight antioxidant as an important factor associated with nickel tolerance. This study also emphasizes the possible important role of luminol-converting peroxidases in nickel hyperaccumulation, although they are not considered as antioxidant enzymes sensu stricto since some of them can also produce reactive oxygen species as well

    Recurrent somatic embryogenesis and plant regeneration from immature zygotic embryos of cabbage (Brassica oleracea var. capitata) and cauliflower (Brassica oleracea var. botrytis)

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    A simple and rapid protocol was established for repetitive somatic embryogenesis and subsequent plant regeneration in two important Brassica oleracea varieties, cabbage and cauliflower. Direct regeneration of somatic embryos (SEs) was achieved from immature zygotic embryos cultured on B5 plant growth regulator (PGR)-free (B5-0) induction medium and on B5 medium supplemented with 1 mg l(-1) 2,4-dichlorophenoxyacetic acid (2,4-D) (B5-D). Zygotic embryos of both cabbage and cauliflower at the cotyledonary (C) stage (1.8 mm long) incubated on B5-0 medium displayed the highest embryo-forming capacities (EFCs) of 11.84 and 11.95, respectively. Secondary somatic embryos (SSEs) appeared on the cabbage and cauliflower's primary embryos at a high frequency (83.3 and 87.5 %, respectively), and this process continued in a repetitive way on PGR-free Murashige and Skoog (MS-0) medium. The embryogenic potential of the cultures with a gradual diminution was maintained for 10 months (ten cycles). A total of 20 % of the mature SSEs from cabbage and 55 % from cauliflower spontaneously regenerated plantlets on MS-0 medium. The addition of 1 mg l(-1) 6-benzyladenine (BA) or 6-furfurylaminopurine (Kin) in the regeneration medium significantly improved somatic embryo conversion into plantlets by up to 56 % in cabbage and 79 % in cauliflower. Regenerated plants acclimated successfully to ex vitro conditions and displayed morphological and reproductive characteristics similar to seed-derived plants. Effective recurrent somatic embryogenesis may be an appropriate practical solution for clonal propagation and genetic modifications of cabbage and cauliflower.[https://link.springer.com/article/10.1007/s11240-012-0279-6

    Antioxidative-related enzyme activity in Alyssum markgrafii shoot cultures as affected by nickel level

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    Shoot cultures of rare Balkan hyperaccumulating species Alyssum markgrafii were subjected to high nickel concentrations of 1, 3, 5, and 8 mM. The effects of graded nickel concentrations on toxicity, pigments, and several components of plant antioxidative defense system were characterized. Toxic effects of excess nickel were observed through slower growth and biomass decrease, together with increased reactive oxygen species (ROS) production and lipid peroxidation. Nickel exposure decreased chlorophyll a, b, total chlorophyll as well as carotenoid concentration. Addition of sodium benzoate, potent ROS scavenger, showed concentration-dependent disturbing effect on nickel hyperaccumulation, lowering the content of accumulated nickel in A. markgrafii shoots. General reducing power represented by low molecular weight antioxidants and phenols was inversely correlated with nickel concentration. Among the investigated antioxidative enzymes, POD seems to play important role in ROS level regulation upon excessive nickel in medium

    Antioxidative-related enzyme activity in Alyssum markgrafii shoot cultures as affected by nickel level

    No full text
    Shoot cultures of rare Balkan hyperaccumulating species Alyssum markgrafii were subjected to high nickel concentrations of 1, 3, 5, and 8 mM. The effects of graded nickel concentrations on toxicity, pigments, and several components of plant antioxidative defense system were characterized. Toxic effects of excess nickel were observed through slower growth and biomass decrease, together with increased reactive oxygen species (ROS) production and lipid peroxidation. Nickel exposure decreased chlorophyll a, b, total chlorophyll as well as carotenoid concentration. Addition of sodium benzoate, potent ROS scavenger, showed concentration-dependent disturbing effect on nickel hyperaccumulation, lowering the content of accumulated nickel in A. markgrafii shoots. General reducing power represented by low molecular weight antioxidants and phenols was inversely correlated with nickel concentration. Among the investigated antioxidative enzymes, POD seems to play important role in ROS level regulation upon excessive nickel in medium.Ministry of Education and Science of Republic of Serbia [173005, 173015

    Xanthone compounds in shoot cultures of Gentianella bulgarica

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    Shoot cultures of Gentianella bulgarica established from seedling epicotyls were maintained on MS medium supplemented with BA 0.2 mg l(-1) + NAA 0.1 mg l(-1). Cultures were prone to precocious flowering requiring the use of small shoot buds for multiplication purposes. The contents of three xanthone compounds identified as DGL, BGL, and DMB, in different plant material were determined by HPLC. The analysis revealed that the production of xanthones was affected by different concentrations of BA in medium. Shoot cultures grown at higher BA concentrations contained more DGL than material grown in nature. The concentrations of other two xanthones were lower in shoot cultures than in plants from nature. The radical scavenging activity of plant extracts and xanthones was investigated by DPPH test. Samples from plants grown in nature showed the highest activity (IC(50) = 0.26 mg ml(-1)), while the extracts of shoot cultures grown in media with higher concentrations of BA showed moderate activities (IC(50) from 1.6 to 4.4 mg ml(-1)).Ministry of Science and Technological Development of Serbia [173015

    Regeneracija pupoljaka in vitro iz eksplantata klijanaca kod povrtarskih kultura roda Brassica - crvenog kupusa, brokolija, kelja i karfiola

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    Brassica oleracea varieties (red cabbage, broccoli, Savoy cabbage and cauliflower) were tested for their ability to regenerate shoots in vitro. Cotyledon, hypocotyl and root explants of 7 day-old seedlings were incubated on Murashige and Skoog's (MS) medium supplemented with 1 mg l-1 6-benzyladenine (BA) or 6-furfurylaminopurine (KIN) in combination with 0, 0.1, and 0.2 mg l-1 indole-3-butyric acid (IBA). Hypocotyls showed the best explants in almost all varieties tested with a minimum regeneration potential of 75% and producing 3.5-7.4 shoots per explant. The BA-supplemented media were optimal for both shoot regeneration and multiplication. Shoots rooted maximally (100%) on plant growth regulator-free MS medium containing 2% or 4% sucrose. Increased sucrose content improved plant acclimation in the greenhouse.Ispitivana je sposobnost četiri varijeteta Brassica oleracea (crveni kupus, brokoli, kelj i karfiol) da regenerišu pupoljke in vitro. Eksplantati kotiledona, hipokotila i korenova, uzetih sa 7 dana starih klijanaca, su gajeni na Murashige i Skoog (MS) hranljivoj podlozi sa dodatkom 1 mg l-1 6-benziladenina (BA) ili 6- furfurilaminopurina (KIN) u kombinaciji sa 0, 0.1, i 0.2 mg l-1 indol-3-butirične kiseline (IBA). Eksplantati hipokotila su se pokazali kao najbolji za regeneraciju kod skoro svih testiranih varijeteta sa minimalnim regenerativnim potencijalom od 75% i sa produkcijom 3.5- 7.4 pupoljaka po eksplantatu. Podloge koje su sadržale BA su bile optimalne, kako za regeneraiju pupoljaka, tako i za njihovu kasniju multiplikaciju. Maksimalan procenat oživljavanja izdanaka (100%) je postignut na MS medijumu bez dodatih regulatora rastenja, a koji je sadržao 2% ili 4% saharozu. Povećan sadržaj saharoze u medijumu za ožiljavanje uticao je na poboljšanu aklimatizaciju biljaka u stakleniku.[http://serbiosoc.org.rs/arch_old/VOL62/SVESKA%202/ABS%2062.2%20-%2018%20-%20Pavlovic.

    Response of unbounded soil in scaled boundary finite-element method

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    The effects of different types and concentrations of sugars on root growth and xanthone production in root culture of Gentiana dinarica were investigated. The results showed that sucrose, glucose and fructose all supported root growth, and sucrose was superior in terms of growth index, dry mass and fresh/dry mass ratio then fructose or glucose at the same concentrations. However, considering equimolar concentration of sugars, their contribution to the root growth was similar. The HPLC analysis of roots indicated the presence of xanthone compounds, and the contents of norswertianin-1-O-primeveroside (1), norswertianin-1-O-glucoside (2), gentioside (3) and norswertianin (4) were evaluated. In all samples, norswertianin-1-O-primeveroside (1) was present in highest concentration, followed by norswertianin-1-O-glucoside (2), whereas gentioside (3) and norswertianin (4) were present in lower amounts. The production of xanthones was affected by both type and concentration of sugar. In general, roots growing in media supplemented with sucrose contained higher levels of xanthones. The amounts of xanthone primeveroses (1) and (3) increased with the increase of concentrations of all types of sugars, whereas higher sugar concentrations resulted in reduction of the contents of norswertianin-1-O-glucoside (2) and aglycone norswertianin (4). The roots were also evaluated regarding the content of total phenolics and higher accumulation of total phenolic compounds was observed in roots grown in fructose-containing medium. Antioxidant activity was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, and high correlation between total phenolic content and antiradical activity was observed (r = -0.83).Ministry of Education, Science and Tecnological Development of Serbia [173015
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