B3.2.7 Uses Of Plant Hormones Flashcards
Auxin function
- stimulate growth by causing cell elongation
- help regulate fruit development
- without auxin fruit=too small
Ethene function
- causes plant fruits to ripen by stimulating the conversion of starch into sugar
- reason why ripe fruit tastes sweeter than un ripe one
- Only plant hormone that exists in gas
Gibberellins function
- promote growth, particularly stem elongation
- end dormancy period of seed & buds
- > leads to shoots and flowers opening
Where is auxin produced?
In high concentration in the merristems / where plant grows
—> roots and shoots
How are plant hormones transported?
They dissolve into fat or water and get transported by the xylem or phloem
Seedless fruit
Parthenocarpy
What does ethene also do?
Cause leaves to fall by stimulating cell connecting rest of plant to expand, break cell wall, fall
4 ways plant hormones used to control plant growth
- Selective herbicides
- Growing from cuttings w root powder
- Parthenocarpic fruit
- Controlling dormancy
Selective herbicides / weed killers
Use auxins to only affect broad leaved plants (weeds)
Disrupt normal growth pattern -killing them
Leaves grass etc untouched
Growing cuttings from rooting powder
Rooting powder contains auxins
Auxins rapidly produce roots and grow as new plant
Enables production of clones of good plants quickly
Seedless fruit
Auxins and gibberellins added to unpollinated flowers of some plants
Fruits grow but seeds don’t
Controlling dormancy
Seeds treated w gibberellins
Alters dormancy and germinates at unusual times of the year
All seeds germinate at same time
