Chemistry and biochemistry of Populus leaf bud resin
| dc.contributor.author | Piirtola, Eerik-Mikael | |
| dc.contributor.supervisor | Constabel, Carsten Peter | |
| dc.date.accessioned | 2024-01-29T17:52:17Z | |
| dc.date.copyright | 2024 | en_US |
| dc.date.issued | 2024-01-29 | |
| dc.degree.department | Department of Biology | |
| dc.degree.level | Doctor of Philosophy Ph.D. | en_US |
| dc.description.abstract | Poplar trees, such as black cottonwood (Populus trichocarpa), balsam poplar (Populus balsamifera), and eastern cottonwood (Populus deltoides) are known to secrete resinous exudate from their leaf buds as their adaptation to temperate climate. The leaf bud resin protects the developing leaf buds from frost during winter dormancy. During bud break, the sticky resin coats the young leaves, protecting against insect herbivory during the early stages of leaf development. Leaf bud resins from different poplar species contain diverse phenolic secondary metabolites, especially hydrophobic flavonoids, which are biologically active. Due to their flavonoid-rich composition, poplar bud resins have been used widely in traditional medicine for their antimicrobial properties. Poplar leaf bud resins are also essential for honeybees, which utilize them as a building material and antibiotic protection for their hives in the form of propolis. In this thesis, I characterized seasonal patterns of leaf bud resin accumulation, as well as genes involved in the biosynthesis of secreted flavonoids in leaf buds of P. trichocarpa, P. balsamifera, and P. deltoides using a combination of metabolomic analysis and transcriptomics. I used targeted and non-targeted analysis of the chemical composition of poplar bud resins to identify and quantify characteristic flavonoids in each poplar species. In parallel with the metabolomic analysis, transcriptomics and biochemical techniques were used to identify and characterize novel genes associated with the production of methoxylated and acylated flavonoids. The identified candidate genes were tested as recombinant proteins to characterize and verify their function. This work provides insight into the dynamic nature of poplar leaf bud resin biosynthesis and the enzymes involved in synthesizing characteristic flavonoids of poplar bud resin. | en_US |
| dc.description.scholarlevel | Graduate | en_US |
| dc.identifier.uri | http://hdl.handle.net/1828/15904 | |
| dc.language | English | eng |
| dc.language.iso | en | en_US |
| dc.rights | Available to the World Wide Web | en_US |
| dc.subject | Populus | en_US |
| dc.subject | metabolomics | en_US |
| dc.subject | leaf bud resin | en_US |
| dc.subject | Populus trichocarpa | en_US |
| dc.subject | Populus balsamifera | en_US |
| dc.subject | Populus deltoides | en_US |
| dc.subject | dihydrochalcone | en_US |
| dc.subject | dihydroflavonol | en_US |
| dc.subject | O-methyltransferase | en_US |
| dc.subject | acyltransferase | en_US |
| dc.subject | poplar | en_US |
| dc.subject | resin | en_US |
| dc.title | Chemistry and biochemistry of Populus leaf bud resin | en_US |
| dc.type | Thesis | en_US |