21 - Plant Communication and Defence Flashcards
(15 cards)
Plants are very vulnerable to attack because they are sessile. What does sessile mean?
They can’t move.
What defence mechanism does a trifolium plant use?
Release poisonous cyanide gas
How do plants search for areas of nutrient-rich patches?
They send out their rhizomes/runners
Mustard plants produce trichome. What does this do?
Trichomes are small leaf hairs to prevent insects from eating the leaves.
What are secondary chemicals?
Secondary chemicals are those that are not directly involved in the normal growth/reproduction of an organism. Rather, they are released when they are attacked. Examples are: o Tannins o Polyphenols o Nicotine o Glycosides o Alkaloids o Nepetalactone
What do Tannins in plants do?
Tannins are a chemical that binds to the protein so the animal can’t benefit from it.
What is the difference between Cyanogenic and Acyanogenic plants?
Cyanogenic plants - release cyanide (defence mechanism)
Acyanogenic plants - don’t
What do acyanogenic plants do when herbivores are present, considering they don’t have a defence mechanism.
They sexually reproduce more.
Methyl Jasmonate and Ethylene are released from damaged plant tissue. Why?
They let the plant know they are being attacked.
Apart from chemical signals, how else can plants know they are being attacked?
- They can detect chewing on tissue (experimentally tested by subjecting the plants to caterpillar eating noises)
- They can detect herbivore saliva
True or false. Plant responses to attack are the same for any herbivore that attacks it.
False. Plant responses can be tailored to a specific herbivore. For example, tobacco and the hawk moth.
Tobacco plants are pollinated by moths at dusk, but they are also eaten by these moths. What did the tobacco plants do to prevent their pollinator from being a predator?
Instead of opening up during dusk, they open up during the day to be pollinated by hummingbirds
True or false? Plants that are under attack can let other plants near it know that they are being attacked.
True. The nearby plants will start releasing their defence mechanisms.
What do sugar maple trees do every few years to avoid their seeds being consumed by squirrels?
They release a massive amount of seeds to ensure a greater chance of survival.
Plants can also attack when other plants are all up in their space. What does the spotted knapweed do in this instance?
It releases catechin in the presence of roots of another species. This is taken up by the roots of the other plant and leads to a cascading physiological and genetic response where the competing plant dies within a few days.
