Abscisic Acid Flashcards
T or F: ABA promote leaves fall?
T
T or F: ABA cause dormancy of seeds and stem buds in the winter?
T
T or F: ABA stimulates germination?
F
T or F: ABA and auxins are synergistic?
F
What is the effect of abscisic acid on plants?
1- ABA plays a role in stem dormancy and leaf fall.
2-ABA aids seed and buds dormancy by inhibiting auxins and growth
What is meant by seed dormancy?
Delaying or preventing seed germination improves a seed’s chances of survival if these conditions aren’t meant.
Why does seed’s dormancy occur?
When the conditions are not available for the seed to grow well, like good light, water and suitable temperature.
How does the seed’s dormancy occur befor the cold season come?
1-ABA is produced.
2- increases its concentration as the day becomes shorter.
3-ABA works against the concentration of hormones that stimulate germination.
4- it triggers a gene that increases the synthesis of plant storage proteins.
How is the dormancy of seed broken as spring approaches?
ABA slowly breaks down over the winter. By the time conditions are favorable again in spring,ABA’s concentration is low, germination and growth hormones take over.
What are the factors that puts the plant under the risk of dehydration?
1- high or low temperatures.
2- strong wind.
3- low humidity.
How the plant adapt under these conditions?
Abscisic acid causes the stomata to close thus preventing water loss.
What is the role of ABA?
1- promote seed dormancy
2- promote stomata closure.
3- inhibits early germination and growth in winter.
