Samuel deck part 2 Flashcards
What do auxins do
Auxins promote growth
what do gibberlins do
Gibberellins also stimulate growth, including the elongation of stems
What do cytokinins do
Cytokinins enhance growth and retard aging
What does ethylene do
Ethylene- Gaseous hormone: regulates a range of responses, including senescence
What do brasstinoids do?
Brassinosteroids regulate plant growth responses
What does ABA do
Abscisic acid suppresses growth and influences responses to environmental stress
What do jasmonates do
make plants taste bad so predators stop munching, has defence role
Whats the acid growth hypothesis on how cells expand?
Auxin pumps of hydrogen ions actively into the cell wall, remember if something is sitting in cell wall- it’s apoplast,
So hydrogen ion concentration in apoplast cause sit to become acidic, this activates the expansin, breaks bridges between cellulose microfibers and therefore allows the cell to expand.
How does auxin cause plants to bend?
Plants are bending towards light source- is this because cells are dividing more to bend towards that area? No that will be too costly for plant, when light hits on one side, auxin accumulation happens on the opposite side which cause the cells to expand on one side which allows the stem to bend towards the light.
Whats bolting
When plant switches from leafy to flowery stem, happens with excess gibberlin
How is gibberlin used in fruit
increases yield
What pathogen caused potato blight?
Pathogen was phytopthora infestans
How do plants react to pathogens?
If there’s a pathogen the plant will kill all cells around it and seal off the xylem, in order to prent pathogen from getting nutrients and entering the plant. They will strengthen cell walls, close stomata, and produce antimicrobial compounds in order to fight the pathogen.
What is systemic required assistance?
Plants can tell other part of the plant that they’re infected, they can also tell neighbouring plants that there are being infected, allows next plant to become immune
Describe the defense mechanism involving tannins
The tannin level goes up when you damage a plant as it make sit bitter so no insect goes on it, the damaged plant sends a signal through air such as ethylene to warn the other plant that there’s a predator which will make it increase it’s tannins
So plants produce volatile induced compounds in undamaged plants to make them less palatable, and they also attract predatory insects that can feed on the organism hurting them such as caterpillars or parasitize the eggs.
