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Browsing by Subject "kasvisoluviljelmä"

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  • Kilpiö, Tommi (2021)
    Plant cell culture can be used for the production of valuable secondary metabolites. Inspired by the previous studies focusing on capsaicinoid production, this study aimed for establishing plant cell cultures of Capsicum chinense to produce capsinoids. Capsinoids are non-pungent capsaicinoid analogues with potential health benefits. Another aim of this study was to determine the α-solanine content in Capsicum plants and cell cultures to ensure that no toxic amounts are formed during the cell culture. Cell cultures of non-pungent Capsicum chinense cultivars, Trinidad Pimento and Aji Dulce strain 2, were established, and the cultures were fed with intermediates, vanillin and vanillyl alcohol, to enhance the production. In addition, cell cultures of extremely pungent Trinidad Scorpion cultivar were established and they were fed with vanillyl alcohol to study if this would result in formation of capsinoids instead of capsaicinoids. A high-performance liquid chromatography (HPLC) method with UV detection was validated for determining the capsiate contents of the cell culture samples and fruit samples for comparison. To analyze the α-solanine content of the cell culture samples and leaves and flowers of three cultivars belonging to three different Capsicum species, an HPLC-UV method was validated for this purpose as well. Despite validating a sensitive and specific method for capsiate analysis, no detectable amounts of capsiate were detected in any of the cell culture samples. Cell cultures of pungent cultivars did not produce detectable amounts of capsaicinoids either. Results from analyzing the real fruit samples were in accordance with previous literature reports, and Aji Dulce fruits were found to contain higher amounts of capsiate compared to Trinidad Pimento, although having only one indoor grown Aji Dulce fruit analyzed limits the reliability. The analytical method for determining α-solanine content had problems with internal standard and specificity. This method could be used for making rough estimates about the possible α-solanine content. No hazardous amounts were detected in any of the cell culture samples. Only one sample consisting of Aji Dulce young leaves could contain α-solanine slightly above the limits set for commercial potatoes. Results with flowers of Rocoto San Pedro Orange (C. pubescens) and Aji Omnicolor (C. baccatum) were inconclusive and it couldn’t be ruled out that they might contain large amounts of α-solanine. The reason why capsinoids, or even capsaicinoids, were not detected in the cell culture samples remains unsolved, but it could be speculated that capsinoids might degrade in the cell culture environment or that selection of cultivar or cell line is critical. This study gave further proof to the previous assumptions that chili leaves are safe and should not contain notable amounts of α-solanine.
  • Åman, Olli (2014)
    Plant cells in plant cell cultures can be used for production of secondary metabolites and recombinant proteins. Producing the desired compounds can be problematic since cells grow slowly, yields can be low and sometimes plant cells do not produce the desired compounds. Yields can be increased by various methods, of which optimisation of growth conditions to favour growth and secondary metabolite biosynthesis is one of various strategies. Light quality is known to have an impact on growth of plants and on accumulation of secondary metabolites. Plants receive information of their environment with photoreceptors, which gives plants ability to alter their morphology and biochemistry to adapt to the prevailing conditions. One of the most important factors involved in controlling morphology and metabolism is activity of bZIP protein HY5, which levels are controlled by degradation by E3 ubiquitin ligase COP1. The photoreceptors are divided to three main groups. A group of Blue/UV-A photoreceptors consists of cryptochromes and phototropins. Phytochromes are photochrome photoreceptors of wavebands of red and far-red. UVR8 photoreceptors are specialized to sense UV-B wavebands. Activated photoreceptors reduce the activity of COP1 individually or inductively. Plant cells contain the same genetic information as intact plants. Object of this study is to investigate effects of different light spectra on plant cell mass pigment accumulation, lipid content and accumulation of secondary metabolites. Additionally, the obtained results can be utilized in designing new artificial light sources to enhance growth and nutritional value of horticultured plants grown under artificial light. VTT's callus cultures established from berries of Rubus (raspberry, cloudberry, arctic bramble) and Vaccinium (lingonberry, bilberry, cranberry) were used in this study. The cell cultures were grown in hormone balanced solid media. For this research Valoya provided four different LED light sources with different spectra, ranging between wavebands 400–800 nm. All berry callus cultures were grown for continuous period of 28–31 days under different light sources. Mass pigments, lipid composition, total phenolic concentration and anthocyanins were analysed from each cell cultures which received different light treatments. Samples were pooled and were by freeze dried and milled. Mass pigments were extracted with acetone and analysis was carried out with UPLC-DAD. Extraction of lipids was carried out with petroleum ether followed with transesterification of glycerolipids and silylation of free fatty acids. The lipid extracts were analysed with GC-MS. Phenolic compounds were extracted with methanol and the extracts were treated with Folin-Ciocalteu's reagent and then analysed with spectrophotometer. Anthocyanins were extracted with acidified methanol and a portion of the extracts were hydrolysed to qualify anthocyanidin moieties of anthocyanins. The extracts and the hydrolysed extract were analysed with UPLC-DAD. Analysis of volatile compounds from each light treated samples was carried out with SPME GC-MS. The obtained results were used to compare concentration differences of the analytes under different light treatments. Correlations between the concentrations of the analytes and different wavebands were possible to establish from the results. Activation of cryptochromes and phytochromes reduced certain lipids that are precursors in LOX-pathway which indicates to increased activity of the pathway. Same wavebands which activated the photoreceptors reduced accumulation of mass pigments, whereas, wavebands of far-red increased the concentrations of mass pigments. In some cases it was observed that small difference in light spectra reduced mass pigment accumulation significantly. The plant cell cultures produced mainly anthocyanins which anthocyanidin moieties were same as in intact plants. Cryptochrome and phytochrome activation increased accumulation of anthocyanins. Yields of anthocyanins can be increased significantly with certain spectra significantly. The effect of light spectra did not have as straightforward effect on total phenolic content. Specie- and linewise differences were observed in light conditions where the highest concentrations of total phenolics were obtained.