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Understanding cannabinoid biosynthesis gene expression in the glandular trichomes of Helichrysum umbraculigerum
Dissertation (MSc (Plant Science))--University of Pretoria, 2017.
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| Format: | Thesis |
| Language: | English |
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2026
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| _version_ | 1867613637506498560 |
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| access_status_str | Open Access |
| author2 | Crampton, Bridget Genevieve |
| author_browse | Crampton, Bridget Genevieve |
| author_facet | Crampton, Bridget Genevieve |
| collection | Thesis |
| description | Dissertation (MSc (Plant Science))--University of Pretoria, 2017. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/110157 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:39:18.847Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2026 |
| publishDateRange | 2026 |
| publishDateSort | 2026 |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/110157 Understanding cannabinoid biosynthesis gene expression in the glandular trichomes of Helichrysum umbraculigerum Crampton, Bridget Genevieve kirstybotha@yahoo.com Heyman, Heino Botha, Kirsty Shannon Cannabinoids Asteraceae Helichrysum umbraculigerum glandular trichome transcriptome Dissertation (MSc (Plant Science))--University of Pretoria, 2017. Cannabinoids are a medicinally important group of compounds. They are best known for their production within Cannabis sativa. These metabolites have been linked to a variety of different medicinal effects, and research into using these compounds for treatments against cancer and neurodegenerative diseases is ongoing. Novel cannabinoids have previously been isolated from the South African plant Helichrysum umbraculigerum (Asteraceae). These may provide unique therapeutic effects however, there is little literature information available regarding this plant. The research presented in this dissertation is intended to bridge the knowledge deficit. This project provides the first in vitro propagation protocol for the efficient production of large amounts of H. umbraculigerum plantlets, which are easily acclimatised. This was done by producing callus culture on media supplemented with plant growth regulators (PGR) at different concentrations. Shoots were produced effectively when the media was supplemented with 4.5 µM thidiazuron (TDZ). The shoots were transferred into boxes containing PGR free media and kept under a 16 h light cycle, where after they produced roots. A cell suspension culture of H. umbraculigerum cells was produced in liquid media containing 5.4 µM of _-naphthaleneacetic acid (NAA). Thin layer chromatography (TLC) was then used to investigate cannabinoid accumulation within H. umbraculigerum. TLC profiles of various plant extracts were compared to cannabinoid standards. These results revealed that cannabigerol (CBG) was found within the leaf, stem, inflorescence, and glandular trichome extracts of H. umbraculigerum. Additionally, it was shown that H. umbraculigerum tissue culture plantlet extracts produced CBG, but cell suspension extracts did not. Two different approaches were used to in order to identify candidate genes involved in cannabinoid biosynthesis from H. umbraculigerum. The first method made use of degenerate primers. This resulted in the amplification PCR products that shared homology with chalcone synthase (CHS) gene fragments. The second approach made use of MiSeq 600 (Illumina®, USA) RNA sequencing. A glandular trichome extraction protocol was optimised for H. umbraculigerum and mRNA was extracted from these structures. From this a de novo transcriptome of the glandular trichomes of H. umbraculigerum was assembled using Trinity 2.0.6. Blast2GO functional annotation analysis was carried out on the resulting assembly, and a candidate list of genes consisting of chalcone synthases, terpene synthases, and monoterpene synthases was complied. These enzymes are likely to produce feeder molecules which form part of the cannabinoid biosynthetic pathway of H. umbraculigerum. The results here represent the first genetic exploration into the cannabinoid biosynthetic genes for this plant. Plant Science MSc (Plant Science) 2026-05-15T17:26:29Z 2026-05-15T17:26:29Z 17/07/05 2017 Dissertation http://hdl.handle.net/2263/110157 en application/pdf |
| spellingShingle | Cannabinoids Asteraceae Helichrysum umbraculigerum glandular trichome transcriptome Understanding cannabinoid biosynthesis gene expression in the glandular trichomes of Helichrysum umbraculigerum |
| title | Understanding cannabinoid biosynthesis gene expression in the glandular trichomes of Helichrysum umbraculigerum |
| title_full | Understanding cannabinoid biosynthesis gene expression in the glandular trichomes of Helichrysum umbraculigerum |
| title_fullStr | Understanding cannabinoid biosynthesis gene expression in the glandular trichomes of Helichrysum umbraculigerum |
| title_full_unstemmed | Understanding cannabinoid biosynthesis gene expression in the glandular trichomes of Helichrysum umbraculigerum |
| title_short | Understanding cannabinoid biosynthesis gene expression in the glandular trichomes of Helichrysum umbraculigerum |
| title_sort | understanding cannabinoid biosynthesis gene expression in the glandular trichomes of helichrysum umbraculigerum |
| topic | Cannabinoids Asteraceae Helichrysum umbraculigerum glandular trichome transcriptome |
| url | http://hdl.handle.net/2263/110157 |