Plant Hormones & Movement. Hormones What do you need to know? 1. Where are they produced? 2. How are...
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Transcript of Plant Hormones & Movement. Hormones What do you need to know? 1. Where are they produced? 2. How are...
Plant Hormones & Movement
HormonesWhat do you need to know?
1. Where are they produced?2. How are they transported?3. How does the plant respond?4. Commercial usesStart with the definition – a chemical that
is produced in one part of the plant, then transported to another where it causes a physiological change.
Auxins
1. Apical meristems2. Active transport3. Weakens fibers to allow growth4. Promotes rooting, inhibits
branching, delays fruit formation & leaf/fruit drop
Gibberellins
1. Location unknown2. Vascular issue3. Stimulate cell division & elongation4. Increased production of grapes,
more malt production in barley (more beer!), increased production of sugar in sugar cane. Breaks dormancy in seeds
Application of gibberellins
Cytokinins1. Roots2. Xylem3. Stimulates mitosis & cell
division when combined with auxins
4. Prolong the storage life of green vegetables (asparagus, broccoli & celery)
Ethylene Gas1. Produced by ripening or dying
tissues2. Diffusion3. Promotes ripening in fruit4. Makes mechanical harvesting
of fruits and veggies easier
Plant responsesTropic response
Slow movement caused by growth - irreversible
Positive tropism – growth is towards stimulus
Negative tropism – growth is away from stimulus
Ex. Phototropism & gravitropism
Nastic movement
Rapid movement caused by change in water pressure - reversible
Response is always the same – not towards or away from stimulus
Ex. – Venus flytrap & Mimosa plants