Volatiles Flashcards
Uses of aromatic essential oils
- Perfumes, scents, flavouring, insect repellant
- Many are terpenes
Examples of terpene aromatics
- Limonene
- Menthol
Where are volatiles often found in plants and why?
- Often found in flowers, leaves, and fruits
- Mostly function for attraction
What is the human use for volatiles?
- Perfumes based on plant essential oils
- 75% are now synthetic
What are some important scent plants?
- Rose, Rosa, Rosaceae, rose family
- Lavender, Lavendula, Lamiaceae, mint family
What is a major challenge in perfume making?
- How to hold the scent
What scents and flavourings are often used to provide ‘taste’ and smell?
- Mint family, Lamiaceae, very rich in aromatic plants
- Citrus family, Rutaceae
Plants in the Mint family
- Menthol, basil, sage, rosemary
- Has the most plants used for their smell
Citrus family and uses of aromatics, limonene
- Fragrant flowers, leaves, and fruit peel
- Limonene, a monoterpene, smell of oranges, lemons
- Oily, can work as solvent in cleaner
- Dissolve styrofoam
- Bergamot orange, oil for Earl Grey tea flavour
What are other functions of plant volatiles in plants?
- Defensive response, herbivore-induced plant volatiles
- Release volatile chemicals to attract natural enemies of herbivores
- Approx. 2000 volatile compounds released in response to herbivore attacks have been identified in many plant families
Experiments that show defensive response of plant volatiles, spider mites
- Plants infested w/ herbivorous spider mites
- Predatory mites go to plants that have been chewed on by spider mites based on odour of infested leaves, ignore control leaves w/ no mites
Experiments that show defensive response of plant volatiles, corn roots
- Corn roots damaged by insect larvae, in ground signal
- Emit signal that attract nematodes to infect insects
- Can be applied to agricultural practice
Defensive response of plants with volatiles
- Released when attacked by herbivores or infesting pests
- Signals predators of herbivores or pests to come to that plant
- Signal can work below ground
- Act as warning signal to other parts of same plant and to neighbouring plants
Why do mountain ranges appear blue in some lighting? What is the purpose for the plant?
- Trees/shrubs emit 500 million tons of isoprene to atm
- Isoprene scatters sunlight at the short wavelengths (blue)
- Gives blue tinge to mountain ranges
- May protect plant photosynthesis from heat