Transcript Auxin? - Hatboro

• Keep an eye out for “The-Owl” and raise
your hand as soon as you see him.
– He will be hiding somewhere in the slideshow
• Keep an eye out for “The-Owl” and raise
your hand as soon as you see him.
– He will be hiding somewhere in the slideshow
“Hoot, Hoot”
“Good Luck!”
• Do plants have brains?
• Answer: No
• Class poll, plants are intelligent.
Yes _______
No __________
Webster Dictionary: Intelligence: noun. The ability to learn
or understand things or to deal with new or difficult
situations.
• Some questions to think about.
– How does a tree know when to drop its leaves?
• When does a plant know when to grow,
and when to remain dormant?
• How does a tree know when spring has
arrived and it’s time to create buds?
• How can a plant move from one side to
another?
– It doesn’t even have muscles.
• How does a plant know when to create
flowers, and what color they should be?
• How does a plant know when the flower has
been fertilized and it’s time to make seeds?
• How does a banana know when to ripen?
• When does a seed know it’s time to
germinate?
• When does a seed know it’s time to
germinate?
– Too early, or too late could be fatal to the young
plant.
• When does a seed know it’s time to
germinate?
– Too early, or too late could be fatal to the young
plant.
• Does anybody know the answer…?
• Answer: Plant Hormones.

New Area of Focus: Plant Hormones.
• Plant hormones are chemicals that affect
flowering;
• Plant hormones are chemicals that affect
flowering; aging;
• Plant hormones are chemicals that affect
flowering; aging; root growth;
• Plant hormones are chemicals that affect
flowering; aging; root growth; distortion,
• Plant hormones are chemicals that affect
flowering; aging; root growth; distortion,
killing of leaves,
• Plant hormones are chemicals that affect
flowering; aging; root growth; distortion,
killing of leaves, stems,
• Plant hormones are chemicals that affect
flowering; aging; root growth; distortion,
killing of leaves, stems, and other parts;
• Plant hormones are chemicals that affect
flowering; aging; root growth; distortion,
killing of leaves, stems, and other parts;
prevention or promotion of stem
elongation;
• Plant hormones are chemicals that affect
flowering; aging; root growth; distortion,
killing of leaves, stems, and other parts;
prevention or promotion of stem
elongation; color enhancement of fruit;
• Plant hormones are chemicals that affect
flowering; aging; root growth; distortion,
killing of leaves, stems, and other parts;
prevention or promotion of stem
elongation; color enhancement of fruit;
prevention of leafing and/or leaf fall;
• Plant hormones are chemicals that affect
flowering; aging; root growth; distortion,
killing of leaves, stems, and other parts;
prevention or promotion of stem
elongation; color enhancement of fruit;
prevention of leafing and/or leaf fall; and
many other conditions.

Plant hormones are chemicals that affect
aspects of the plants life.

Some plant hormones.
 -Auxin
 -Gibberelins
 -Cytokinins
 -Abscisic
Acid
 -Ethylene
• Do plants move?
• Video Link! Plants searching for light.
• Plants do move, although this movement is
very little. (Not animal like)

Auxin: Promotes stem elongation and bud
dormancy.
 Phototropism:
light source.
When plants grow toward a
Copyright © 2010 Ryan P. Murphy

Auxin: Promotes stem elongation and bud
dormancy.
 Phototropism:
light source.
When plants grow toward a
• A plant moves by elongating the cells on
the opposite side of light, causing the plant
to bend toward the light.
• Activity! Feeling phototropism in plants.
• Activity! Feeling phototropism in plants.
– Stand up tall, feet slightly apart, and bend
toward the light.
Copyright © 2010 Ryan P. Murphy
• Activity! Feeling phototropism in plants.
– Stand up tall, feet slightly apart, and bend
toward the light.
– What part of your body elongates / stretches,
and which shrinks in?
• Note: Plants do not have muscles, so the
elongation and contraction occurs on a
cellular level.
• Note: Plants do not have muscles, so the
elongation and contraction occurs on a
cellular level.
Shorted
Cells
• Note: Plants do not have muscles, so the
elongation and contraction occurs on a
cellular level.
Elongated
Cells
Shorted
Cells
• Note: Plants do not have muscles, so the
elongation and contraction occurs on a
cellular level.
Elongated
Cells
Shorted
Cells
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of in response to gravity and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Auxin also…
– Stimulates cell division.
– Stimulates differentiation of phloem and xylem
– Response of bending in response to gravity
and light.
– Delays growth of lateral buds.
– Can induce fruit setting and growth in some
plants.
– Delays fruit ripening.
– Stimulates growth of flower parts.
• Which plant was given extra gibberellin
hormones?
• Plant A shows extra
stem elongation over
plant B.

Gibberellins: Make stems longer.
Copyright © 2010 Ryan P. Murphy
• Gibberellins also…
– Stimulates flowering in
response to long days.
– Breaks seed dormancy
– Induces maleness in
some flowers (sex
expression).
– Can cause fruit
development.
– Can delay dropping of
leaves and citrus fruits.
Copyright © 2010 Ryan P. Murphy
• Gibberellins also…
– Stimulates flowering in
response to long days.
– Breaks seed dormancy
– Induces maleness in
some flowers (sex
expression).
– Can cause fruit
development.
– Can delay dropping of
leaves and citrus fruits.
Copyright © 2010 Ryan P. Murphy
• Gibberellins also…
– Stimulates flowering in
response to long days.
– Breaks seed dormancy
– Induces maleness in
some flowers (sex
expression).
– Can cause fruit
development.
– Can delay dropping of
leaves and citrus fruits.
• Gibberellins also…
– Stimulates flowering in
response to long days.
– Breaks seed dormancy
– Induces maleness in
some flowers (sex
expression).
– Can cause fruit
development.
– Can delay dropping of
leaves and citrus fruits.
• Gibberellins also…
– Stimulates flowering in
response to long days.
– Breaks seed dormancy
– Induces maleness in
some flowers (sex
expression).
– Can cause fruit
development.
– Can delay dropping of
leaves and citrus fruits.
• Gibberellins also…
– Stimulates flowering in
response to long days.
– Breaks seed dormancy
– Induces maleness in
some flowers (sex
expression).
– Can cause fruit
development.
– Can delay dropping of
leaves and citrus fruits.
• Which is Auxin and which is Gibberellins?
• Which is Auxin and which is Gibberellins?
• Which is Auxin and which is Gibberellins?
• Which is Auxin and which is Gibberellins?
• Which is Auxin and which is Gibberellins?

Cytokinins: Promotes cell division. They
are produced in growing areas like the
tips.
Root Tip

Abscisic Acid: Opens and closes stomata,
has role in seed dormancy.
• Note: Stomata are small pores (openings)
for gas exchange.
• Note: Stomata are small pores (openings)
for gas exchange.
• Note: Stomata are small pores (openings)
for gas exchange.
• Abscisic Acid…
– Inhibits shoot growth.
• Abscisic Acid…
– Inhibits shoot growth.
• Abscisic Acid…
– Inhibits shoot growth.
– Induces seeds to synthesize storage proteins.
– Helps to recognize and fix wounding on an
injured plant.
• What does the one bad apple do…?
• What does the one bad apple do…?
• What does the one bad apple do…?
– Why?
• What does the one bad apple do…?
– Why?
• What does the one bad apple do…?
– Why?
• One bad apple spoils the bunch because that
bad apple is releasing ethylene gas which
causes the others to ripen.
• One bad apple spoils the bunch because that
bad apple is releasing ethylene gas which
causes the others to ripen.
• One bad apple spoils the bunch because that
bad apple is releasing ethylene gas which
causes the others to ripen.
– Remove ripe fruit from the bunch to keep fruit
longer.

Ethelyene: A gas that promotes fruit
ripening.
• Ethylene also…
– Stimulates the release of seed dormancy.
– Stimulates shoot and root growth.
– Stimulates leaf and fruit abscission.
– Creates femaleness in flowers.
– Stimulates flower opening.
– Stimulates flower and leaf dying.
• Ethylene also…
– Stimulates the release of seed dormancy.
– Stimulates shoot and root growth.
– Stimulates leaf and fruit abscission.
– Creates femaleness in flowers.
– Stimulates flower opening.
– Stimulates flower and leaf dying.
• Ethylene also…
– Stimulates the release of seed dormancy.
– Stimulates shoot and root growth.
– Stimulates leaf and fruit abscission.
– Creates femaleness in flowers.
– Stimulates flower opening.
– Stimulates flower and leaf dying.
• Ethylene also…
– Stimulates the release of seed dormancy.
– Stimulates shoot and root growth.
– Stimulates leaf and fruit abscission.
– Creates femaleness in flowers.
– Stimulates flower opening.
– Stimulates flower and leaf dying.
• Ethylene also…
– Stimulates the release of seed dormancy.
– Stimulates shoot and root growth.
– Stimulates leaf and fruit abscission.
– Creates femaleness in flowers.
– Stimulates flower opening.
– Stimulates flower and leaf dying.
• Ethylene also…
– Stimulates the release of seed dormancy.
– Stimulates shoot and root growth.
– Stimulates leaf and fruit abscission.
– Creates femaleness in flowers.
– Stimulates flower opening.
– Stimulates flower and leaf dying.
• Ethylene also…
– Stimulates the release of seed dormancy.
– Stimulates shoot and root growth.
– Stimulates leaf and fruit abscission.
– Creates femaleness in flowers.
– Stimulates flower opening.
– Stimulates flower and leaf dying.
• Which one is Absic Acid and which is
cytokinins?
• Which one is Absic Acid and which is
cytokinins?
• Which one is Absic Acid and which is
cytokinins?
• Which one is Absic Acid and which is
cytokinins?
• Which one is Absic Acid and which is
cytokinins?
• Which one is the plant hormone ethylene?
• Which one is the plant hormone ethylene?
• Which one is the plant hormone ethylene?
• Which one is the plant hormone ethylene?
• Which one is the plant hormone ethylene?
• Which is Auxin and which is Gibberellins?
• Which is Auxin and which is Gibberellins?
• Which is Auxin and which is Gibberellins?
• Which is Auxin and which is Gibberellins?
• Which is Auxin and which is Gibberellins?
• Class poll, Are plants intelligent / more
complicated, and perform exciting
processes that you never thought of until
studying plant hormones?
Yes _______
No __________
Learn more about plant hormones (Advanced) at…
http://www.plant-hormones.info/ Easier at…
http://www.ext.colostate.edu/mg/gardennotes/145.html
• Try and figure out what picture is beneath
the boxes.
– Raise your hand when you know. You only
get one guess.