Volatiles

Question 1

Uses of aromatic essential oils

Answer 1

• Perfumes, scents, flavouring, insect repellant

- Many are terpenes

Question 2

Examples of terpene aromatics

Answer 2

• Limonene

- Menthol

Question 3

Where are volatiles often found in plants and why?

Answer 3

• Often found in flowers, leaves, and fruits

- Mostly function for attraction

Question 4

What is the human use for volatiles?

Answer 4

• Perfumes based on plant essential oils

- 75% are now synthetic

Question 5

What are some important scent plants?

Answer 5

• Rose, Rosa, Rosaceae, rose family

- Lavender, Lavendula, Lamiaceae, mint family

Question 6

What is a major challenge in perfume making?

Answer 6

• How to hold the scent

Question 7

What scents and flavourings are often used to provide ‘taste’ and smell?

Answer 7

• Mint family, Lamiaceae, very rich in aromatic plants

- Citrus family, Rutaceae

Question 8

Plants in the Mint family

Answer 8

• Menthol, basil, sage, rosemary

- Has the most plants used for their smell

Question 9

Citrus family and uses of aromatics, limonene

Answer 9

• 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

Question 10

What are other functions of plant volatiles in plants?

Answer 10

• 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

Question 11

Experiments that show defensive response of plant volatiles, spider mites

Answer 11

• 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

Question 12

Experiments that show defensive response of plant volatiles, corn roots

Answer 12

• Corn roots damaged by insect larvae, in ground signal
• Emit signal that attract nematodes to infect insects
• Can be applied to agricultural practice

Question 13

Defensive response of plants with volatiles

Answer 13

• 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

Question 14

Why do mountain ranges appear blue in some lighting? What is the purpose for the plant?

Answer 14

• 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