Hormones Flashcards
Where are Auxins synthesized?
Primarily in the lead primordial and young leaves and in developing seeds.
How is Auxin transported?
Both polarly (unidirectionaly; through vascular parenchyma cells) and nonpolarly (through sieve tubes in phloem).
What are the effects of Auxin?
Apical dominance, vascular tissue differentiation, induction of adventitious root, inhibition of leaf and fruit abscission. Stimulation of fruit development.
Where are Cytokinins synthesized?
Primarily in root tips
How are Cytokinins transported?
Via the xylem from the roots to the shoot.
What are the effects of Cytokinins?
Promotion of cell division, promotion of shoot formation, delay of leaf senescence.
Where is Ethylene synthesized?
In most tissues in response to stress, especially in tissues undergoing senescence or ripening.
How is ethylene transported?
Since it’s a gas, it moves by diffusion.
What are the effects of ethylene?
Fruit ripening, leaf and flower senescence; leaf and fruit abscission.
Where is Abscisic acid synthesized?
In mature leaves and roots, especially in response to water stress. May be synthesized in seeds.
How is Abscisic Acid transported?
From leaves in the phloem. From the roots in the xylem.
What are the effects of Abscisic Acid?
Stimulates closing of stomata. Promotes seed desiccation. Inhibits seed germination.
Where are Gibberellins synthesized?
In young tissues of the shoot and developing seeds.
How are Gibberellins transported?
Probably transported in xylem and phloem.
What are the effects of Gibberellins?
Control shoot elongation. Induction of seed germination. Regulation of seed enzymes in cereals.
