Browsing by Author "Trendafilova A."

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Application of Organic Nanofibers to Boost Specialized Metabolite Production and Antioxidant Potential in Stevia rebaudiana In Vitro Cultures
    (2025-09-01) Geneva M.; Trendafilova A.; Miladinova-Georgieva K.; Sichanova M.; Tsekova D.; Ivanova V.; Kirova E.; Petrova M.
    Background: Potential advantages for improving plant growth, stress tolerance, and valuable metabolites generation are provided by the implementation of nanotechnology into plant biotechnology. A recently discovered technique with significant promise for agricultural practices is the use of biopolymer-based nanomaterials, like peptidomimetics, as insecticides, growth regulators, and nutrient carriers. This study explores the impact of biopolymer-based organic nanofibers—specifically peptidomimetics formed through the self-assembly of L-valine and nicotinic acid (NA) (denoted as M6) on Stevia rebaudiana in vitro propagation and specialized metabolite production. The central hypothesis was that such nanofibers, particularly when used as hormone carriers, can beneficially influence plant morphology, physiology, and biochemistry, thereby promoting the synthesis of antioxidant compounds with therapeutic potential. Methods: The nanofibers were tested either alone (M6) or as carriers of the plant hormone indole-3-acetic acid (IAA) (M6+IAA), supplemented to the cultivation MS medium at variable concentrations (0, 1, 10, and 50 mg L−1). Results: The results revealed that treatment with 10 mg L−1 M6 significantly enhanced shoot growth parameters, including the highest fresh weight (0.249 g), mean shoot height (9.538 cm), shoot number (1.95), and micropropagation rate. Plants treated with M6 alone outperformed those treated with M6+IAA in terms of shoot growth, total soluble sugars, and steviol glycoside content. Conversely, M6+IAA treatment more effectively promoted root initiation, the increased accumulation of mono- and dicaffeoylquinic acids, and boosted antioxidant enzyme activity. Conclusions: These findings highlight the potential of organic nanofibers, both with and without hormone loading, as novel tools for optimizing micropropagation and metabolite enhancement in Stevia rebaudiana.
  • No Thumbnail Available
    Item
    Improvement of Stevia rebaudiana Bertoni In Vitro Propagation and Steviol Glycoside Content Using Aminoacid Silver Nanofibers
    (2022-10-01) Sichanova M.; Geneva M.; Petrova M.; Miladinova-Georgieva K.; Kirova E.; Nedev T.; Tsekova D.; Iwanov I.; Dochev K.; Ivanova V.; Trendafilova A.
    The food industry is interested in replacing artificial sweeteners with natural sugars that possess zero calories and carbohydrates and do not cause spikes in blood sugar levels. The steviosides leaves, synthesized at Stevia rebaudiana Bertoni, are 300 times sweeter than common table sugar. Stevia propagation is limited due to the poor viability of the seeds, the long time and low germination rate, and the poor rooting ability of vegetative cuttings. Because of this, an alternative biotechnological method for its reproduction is being studied, such as multiple shoot production through direct organogenesis using nanofibers, formed from a derivative of amino acid valine as a carrier of the biologically active agent silver atoms/particles (NF-1%Ag and NF-2%Ag). The stevia explants were cultured on a medium containing NF-1%Ag and NF-2%Ag at concentrations of 1, 10, 50, and 100 mg L−1. The NF-1%Ag and NF-2%Ag treatment caused hormetic effects on stevia plantlets. At low concentrations of from 1 to 50 mg L−1 of nanofibers, the stimulation of plant growth was observed, with the maximum effect being observed at 50 mg L−1 nanofibers. However, at the higher dose of 100 mg L−1, inhibition of the values of parameters characterizing plant growth was recorded. The presence of nanofibers in the medium stimulates stevia root formatting.
  • No Thumbnail Available
    Item
    Influence of the Abiotic Elicitors Ag Salts of Aspartic Acid Derivatives, Self-Organized in Nanofibers with Monomeric and Dimeric Molecular Structures, on the Antioxidant Activity and Stevioside Content in Micropropagated Stevia rebaudiana Bert.
    (2023-10-01) Sichanova M.; Geneva M.; Petrova M.; Miladinova-Georgieva K.; Kirova E.; Nedev T.; Tsekova D.; Ivanova V.; Trendafilova A.
    The use of nanomaterials in biotechnology for the in vitro propagation of medical plants and the accumulation of certain biologically active metabolites is becoming an efficient strategy. This study aimed to evaluate the influence of the concentration (0, 1, 10, 50, and 100 mg L−1) of two types of nanofibers on the growth characteristics, the antioxidant status, and the production of steviol glycosides in micropropagated Stevia rebaudiana Bert. plantlets. The nanofibers were synthesized by aspartic acid derivatives (L-Asp) Ag salts self-organized into nanofibers with two different molecular structures: monomeric, containing one residue of L-Asp with one hydrophilic head which bonds one Ag ion (NF1-Ag salt); and dimeric, containing two residues of L-Asp with two hydrophilic heads which bond two Ag ions (NF2-Ag salt). An increase in the shoots from the explants’ number and length, biomass accumulation, and micropropagation rate was achieved in the plants treated with the NF1-Ag salt in concentrations from 1 to 50 mg L−1 after 30 days of in vitro proliferation compared to the NF2-Ag salt. In contrast, the plants grown on MS media supplemented with NF2-Ag salt exhibited an increase in the level of stevioside, rebaudioside A, and mono- (CQA) and dicaffeoylquinic (DCQA) acids as compared to the NF1-Ag salt.