growth responses and regulation of growth chapter 11
TRANSCRIPT
![Page 1: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/1.jpg)
Growth Responses and Growth Responses and Regulation of GrowthRegulation of Growth
Chapter 11Chapter 11
![Page 2: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/2.jpg)
![Page 3: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/3.jpg)
LEARNING OBJECTIVESLEARNING OBJECTIVES• 1 Discuss genetic and environmental factors that affect 1 Discuss genetic and environmental factors that affect
plant growth and development . plant growth and development . • 2 Describe phototropism, gravitropism, and 2 Describe phototropism, gravitropism, and
thigmotropism . thigmotropism . • 3 List several ways in which each of the following hor-3 List several ways in which each of the following hor-
mones affects plant growth and development: auxin, gib-mones affects plant growth and development: auxin, gib-berellin, cytokinin, ethylene, abscisic acid. berellin, cytokinin, ethylene, abscisic acid.
• 4 Relate which hormone or hormones is/ are involved in 4 Relate which hormone or hormones is/ are involved in each of the following biological processes: leaf each of the following biological processes: leaf abscission, seed germination, apical dominance. abscission, seed germination, apical dominance.
• 5 Explain how varying amounts of light and darkness 5 Explain how varying amounts of light and darkness induce flowering, and describe the role of phytochrome. induce flowering, and describe the role of phytochrome.
• 6 Explain how temperature affects flower induction in 6 Explain how temperature affects flower induction in certain plants. certain plants.
• 7 Define circadian rhythm, and give an example. 7 Define circadian rhythm, and give an example. • 8 Give an example of a turgor movement, and distinguish 8 Give an example of a turgor movement, and distinguish
between turgor movements and tropisms.between turgor movements and tropisms.
![Page 4: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/4.jpg)
LEARNING OBJECTIVE 1LEARNING OBJECTIVE 1
• Discuss Discuss geneticgenetic and and environmental environmental factorsfactors that affect plant growth and that affect plant growth and development development
![Page 5: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/5.jpg)
Internal Genetic FactorsInternal Genetic Factors
• The location of a cell in the young plant The location of a cell in the young plant body affects gene expression during body affects gene expression during development development
• Causes some genes in that cell to be Causes some genes in that cell to be turned off and others to be turned on turned off and others to be turned on
![Page 6: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/6.jpg)
External Environmental FactorsExternal Environmental Factors
• Factors in the physical environment Factors in the physical environment determine gene expression, affect plant determine gene expression, affect plant growth and development growth and development • changing day lengthchanging day length• variation in precipitationvariation in precipitation• temperature temperature
![Page 7: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/7.jpg)
Spring FlowersSpring Flowers
![Page 8: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/8.jpg)
LEARNING OBJECTIVE 2LEARNING OBJECTIVE 2
• Describe Describe phototropism, gravitropism,phototropism, gravitropism, and and thigmotropismthigmotropism
![Page 9: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/9.jpg)
TropismsTropisms
• Are directional growth responsesAre directional growth responses
• Are permanent Are permanent
![Page 10: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/10.jpg)
KEY TERMSKEY TERMS
• PHOTOTROPISM PHOTOTROPISM • Directional growth of a plant caused by lightDirectional growth of a plant caused by light
• GRAVITROPISM GRAVITROPISM • Plant growth in response to direction of gravityPlant growth in response to direction of gravity
• THIGMOTROPISMTHIGMOTROPISM • Growth in response to contact with a solid objectGrowth in response to contact with a solid object
![Page 11: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/11.jpg)
PhototropismPhototropism
![Page 12: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/12.jpg)
GravitropismGravitropism
![Page 13: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/13.jpg)
Fig. 11-3a, p. 223
![Page 14: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/14.jpg)
On day 3, turned onits side
One hour later
Fig. 11-3a, p. 223
![Page 15: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/15.jpg)
Fig. 11-3b, p. 223
![Page 16: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/16.jpg)
Darwins’ ExperimentsDarwins’ Experiments
![Page 17: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/17.jpg)
Fig. 11-4a, p. 224
![Page 18: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/18.jpg)
Fig. 11-4b, p. 224
![Page 19: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/19.jpg)
Light rays
(a) (b) (c) (d)
Fig. 11-4b, p. 224
![Page 20: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/20.jpg)
Auxin in ColeoptilesAuxin in Coleoptiles
![Page 21: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/21.jpg)
Agar block
Coleoptile tip
(a) (b) (c)
Fig. 11-5, p. 225
![Page 22: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/22.jpg)
LEARNING OBJECTIVE 3LEARNING OBJECTIVE 3
• List several ways in which each of the List several ways in which each of the following hormones affects plant following hormones affects plant growth and development: growth and development: auxin, auxin, gibberellin, cytokinin, ethylene, gibberellin, cytokinin, ethylene, abscisic acidabscisic acid
![Page 23: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/23.jpg)
KEY TERMSKEY TERMS
• HORMONE HORMONE • An organic chemical messenger that An organic chemical messenger that
regulates growth and development in plants regulates growth and development in plants and other multicellular organismsand other multicellular organisms
![Page 24: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/24.jpg)
Communication MoleculesCommunication Molecules
• Five major classes of plant Five major classes of plant hormoneshormones• auxin, gibberellin, cytokinin, ethylene, auxin, gibberellin, cytokinin, ethylene,
abscisic acidabscisic acid
• A variety of signaling molecules A variety of signaling molecules
![Page 25: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/25.jpg)
KEY TERMSKEY TERMS
• AUXIN AUXIN • Plant hormone involved in growth and Plant hormone involved in growth and
development, including stem elongation, development, including stem elongation, apical dominance, and root formation on apical dominance, and root formation on cuttingscuttings
![Page 26: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/26.jpg)
Animation: PhototropismAnimation: Phototropism
CLICKTO PLAY
![Page 27: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/27.jpg)
Auxin and PhototropismAuxin and Phototropism
![Page 28: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/28.jpg)
Light rays
Illuminatedside ofcoleoptile
Shaded sideof coleoptile
Aux
in
Fig. 11-6, p. 226
![Page 29: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/29.jpg)
Auxin and Auxin and Root DevelopmentRoot Development
![Page 30: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/30.jpg)
Animation: Auxin’s EffectsAnimation: Auxin’s Effects
CLICKTO PLAY
![Page 31: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/31.jpg)
KEY TERMSKEY TERMS
• GIBBERELLINGIBBERELLIN • Plant hormone involved in growth and Plant hormone involved in growth and
development, including stem elongation, development, including stem elongation, flowering, and seed germinationflowering, and seed germination
![Page 32: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/32.jpg)
Effects of GibberelinEffects of Gibberelin
![Page 33: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/33.jpg)
KEY TERMSKEY TERMS
• CYTOKININCYTOKININ • Plant hormone involved in growth and Plant hormone involved in growth and
development, including cell division and delay development, including cell division and delay of senescenceof senescence
![Page 34: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/34.jpg)
Hormones and Tissue CultureHormones and Tissue Culture
![Page 35: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/35.jpg)
(a) Initialexplant
b) Callus (c) Roots d) Shoots
Cell divisionwithout differentiation
Cell divisionwith differentiation
Fig. 11-10, p. 229
![Page 36: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/36.jpg)
Cytokinin and Cytokinin and SenescenceSenescence
![Page 37: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/37.jpg)
KEY TERMSKEY TERMS
• ETHYLENE ETHYLENE • A gaseous plant hormone involved in growth A gaseous plant hormone involved in growth
and development, including leaf abscission and development, including leaf abscission and fruit ripeningand fruit ripening
![Page 38: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/38.jpg)
Ethylene and Fruit RipeningEthylene and Fruit Ripening
![Page 39: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/39.jpg)
KEY TERMSKEY TERMS
• ABSCISIC ACIDABSCISIC ACID • A plant hormone involved in growth and A plant hormone involved in growth and
development, including dormancy and development, including dormancy and responses to stressresponses to stress
![Page 40: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/40.jpg)
Other Signaling MoleculesOther Signaling Molecules
![Page 41: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/41.jpg)
Day-neutral plant graftedto long-day plant
Both plants flower
Long-dayinductionGraft
Fig. 11-14, p. 232
![Page 42: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/42.jpg)
![Page 43: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/43.jpg)
Plant cell responses to infection by fungi, bacteria, or viruses. As aresult of an initial infection and a subsequent signal-transduction pathway, plants produce a variety of antimicrobial molecules
![Page 44: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/44.jpg)
Signal TransductionSignal Transduction
![Page 45: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/45.jpg)
Ubiquitin isattached to proteinsthat inhibit certaingenes.
Inhibited genesare turned on.
Nuclear envelope
DNA (contains genes)
Nucleus
Cell wallPlasma membrane
Proteins aredestroyed.
Cytoplasm
ProteinAuxin bindsto receptor.
Auxin
Ubiquitin
Receptor
2
4
31
Fig. 11-15, p. 233
![Page 46: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/46.jpg)
Cytoplasm
Plasma membrane Cell wall
Nuclear envelope
Nucleus
Stepped Art
Proteins are targeted for destruction.
3
Previously repressed genes are activated and expressed.
Transcription
DNA
4Ubiquitin
2 Ubiquitin is tagged to proteins that inhibit certain genes.
Protein
Auxin
1 Auxin binds to TIR1 receptor.
Receptor
Fig. 11-15, p. 233
![Page 47: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/47.jpg)
LEARNING OBJECTIVE 4LEARNING OBJECTIVE 4
• Relate which hormone or hormones Relate which hormone or hormones is/are involved in each of the following is/are involved in each of the following biological processes: biological processes: leaf abscissionleaf abscission, , seed germinationseed germination, , apical dominanceapical dominance
![Page 48: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/48.jpg)
Leaf AbscissionLeaf Abscission
• Ethylene and auxin Ethylene and auxin • As a leaf ages, auxin level in the leaf As a leaf ages, auxin level in the leaf
decreases, and ethylene level increases decreases, and ethylene level increases
![Page 49: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/49.jpg)
Seed GerminationSeed Germination
• Gibberellins involved in seed germinationGibberellins involved in seed germination• in certain plants (cereals, grasses) in certain plants (cereals, grasses) • substitutes for low-temperature or light substitutes for low-temperature or light
requirements in some seeds (lettuce, oats, requirements in some seeds (lettuce, oats, tobacco)tobacco)
• Ethylene and abscisic acidEthylene and abscisic acid• Ethylene promotes seed germination; abscisic Ethylene promotes seed germination; abscisic
acid inhibits seed germination acid inhibits seed germination
![Page 50: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/50.jpg)
Abscisic Acid and GerminationAbscisic Acid and Germination
![Page 51: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/51.jpg)
Apical Dominance 1Apical Dominance 1
• Inhibition of axillary bud growth by the Inhibition of axillary bud growth by the apical meristemapical meristem
• Auxin Auxin • Produced in shoot apical meristemProduced in shoot apical meristem• Inhibits axillary buds near apical meristem Inhibits axillary buds near apical meristem
from developing into actively growing shoots from developing into actively growing shoots
![Page 52: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/52.jpg)
Apical Dominance 2Apical Dominance 2
• Cytokinins and ethylene Cytokinins and ethylene • Cytokinins promote growth of axillary buds; Cytokinins promote growth of axillary buds;
ethylene inhibits axillary bud developmentethylene inhibits axillary bud development
![Page 53: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/53.jpg)
Auxin and Auxin and Axillary Bud DevelopmentAxillary Bud Development
![Page 54: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/54.jpg)
LEARNING OBJECTIVE 5LEARNING OBJECTIVE 5
• Explain how varying amounts of light Explain how varying amounts of light and darkness induce flowering and darkness induce flowering
• Describe the role of Describe the role of phytochromephytochrome
![Page 55: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/55.jpg)
KEY TERMSKEY TERMS
• PHOTOPERIODISMPHOTOPERIODISM • Physiological response (such as flowering) of Physiological response (such as flowering) of
plants to variations in length of daylight and plants to variations in length of daylight and darknessdarkness
![Page 56: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/56.jpg)
PhotoperiodismPhotoperiodism
• Some plants are Some plants are short-day plantsshort-day plants, , some some are are long-day plants, long-day plants, others areothers are intermediate-day plantsintermediate-day plants • Plant measures length of dark period Plant measures length of dark period
• In In day-neutral plantsday-neutral plants, , photoperiod does photoperiod does not affect flowering not affect flowering
![Page 57: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/57.jpg)
Short-Day PlantsShort-Day Plants
![Page 58: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/58.jpg)
Photoperiodic ResponsesPhotoperiodic Responses
![Page 59: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/59.jpg)
Black-eyed Susan (long-day/short-night plant)
Chrysanthemum (short-day/ long-night plant)
(a) Short daysand long nights
(b) Long daysand short nights
(c) Short daysand long nights(interrupted witha brief period oflight)
(d) Long days(interrupted witha brief period ofdark) and shortnights
Day Night
1
2
Fig. 11-17, p. 234
![Page 60: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/60.jpg)
KEY TERMSKEY TERMS
• PHYTOCHROMEPHYTOCHROME • A blue-green proteinaceous pigment involved A blue-green proteinaceous pigment involved
in many plant responses to light, independent in many plant responses to light, independent of photosynthesisof photosynthesis
![Page 61: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/61.jpg)
PhytochromePhytochrome
• There are about five different phytochrome There are about five different phytochrome proteins proteins
• Each exists in two forms and readily Each exists in two forms and readily converts from one form to the other after converts from one form to the other after absorption of light of specific wavelengths absorption of light of specific wavelengths
![Page 62: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/62.jpg)
Phytochrome FormsPhytochrome Forms
• PrPr s strongly absorbs red light with a trongly absorbs red light with a relatively short wavelength (660 nm)relatively short wavelength (660 nm)• Changes to the second form Changes to the second form (Pfr)(Pfr)
• PfrPfr absorbs red light with a relatively long absorbs red light with a relatively long wavelength (730 nm)wavelength (730 nm)• The active form, triggers or inhibits responses The active form, triggers or inhibits responses
such as floweringsuch as flowering
![Page 63: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/63.jpg)
Phytochrome ConversionPhytochrome Conversion
![Page 64: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/64.jpg)
Physiologicalresponse(such as
flowering)
Far-red light(730 nm)
Short-livedintermediate forms Pfr
Active form
Red light (660 nm)
Pr
Inactiveform
Short-livedintermediate forms
Fig. 11-18, p. 235
![Page 65: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/65.jpg)
Animation: Phytochrome Animation: Phytochrome ConversionsConversions
CLICKTO PLAY
![Page 66: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/66.jpg)
LEARNING OBJECTIVE 6LEARNING OBJECTIVE 6
• Explain how temperature affects flower Explain how temperature affects flower induction in certain plantsinduction in certain plants
![Page 67: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/67.jpg)
Temperature RequirementsTemperature Requirements
• Certain plants have temperature Certain plants have temperature requirements that must be met in order for requirements that must be met in order for them to flowerthem to flower
![Page 68: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/68.jpg)
KEY TERMSKEY TERMS
• VERNALIZATIONVERNALIZATION • The low-temperature requirement for The low-temperature requirement for
flowering in some plant speciesflowering in some plant species
![Page 69: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/69.jpg)
Temperature RequirementsTemperature Requirements
![Page 70: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/70.jpg)
LEARNING OBJECTIVE 7LEARNING OBJECTIVE 7
• Define Define circadian rhythmcircadian rhythm
• Give an exampleGive an example
![Page 71: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/71.jpg)
KEY TERMSKEY TERMS
• CIRCADIAN RHYTHMCIRCADIAN RHYTHM • A biological activity with an internal rhythm A biological activity with an internal rhythm
that approximates the 24-hour daythat approximates the 24-hour day
![Page 72: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/72.jpg)
Circadian RhythmsCircadian Rhythms
• Reset by the rising and setting of the sun Reset by the rising and setting of the sun
• Circadian rhythms in plants affect Circadian rhythms in plants affect • gene expression gene expression • rate of photosynthesisrate of photosynthesis• opening and closing of stomataopening and closing of stomata
![Page 73: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/73.jpg)
Sleep MovementsSleep Movements
![Page 74: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/74.jpg)
LEARNING OBJECTIVE 8LEARNING OBJECTIVE 8
• Give an example of a turgor movement, Give an example of a turgor movement, and distinguish between and distinguish between turgor turgor movementsmovements and and tropismstropisms
![Page 75: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/75.jpg)
KEY TERMSKEY TERMS
• TURGOR MOVEMENTTURGOR MOVEMENT • Temporary plant movement that results from Temporary plant movement that results from
changes in internal water pressure in a plant changes in internal water pressure in a plant partpart
• Examples:Examples: Leaves of the sensitive plant and Leaves of the sensitive plant and Venus flytrap Venus flytrap
![Page 76: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/76.jpg)
Sensitive PlantSensitive Plant
![Page 77: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/77.jpg)
Fig. 11-21a, p. 237
![Page 78: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/78.jpg)
Fig. 11-21b, p. 237
![Page 79: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/79.jpg)
Fig. 11-21c, p. 237
![Page 80: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/80.jpg)
(c) How the folding and drooping occurs. Pulvini occur in three areas: thebase of each leaflet, the base of each cluster of leaflets, and the base of eachleaf. Only changes in the pulvini at the bases of leaflets are shown. (Top right)A section through two leaflets, showing their pulvini when the leaf is undisturbed.(Bottom right) A section through the two leaflets, showing how a lossof turgor produces the folding of the leaves.
Leafletopen Leaflet
Pulvinus
Vasculartissue
Decrease ofturgor inparenchymacells
Parenchymacells retainingturgor
Cross-sectional views
Leafletfolded
Fig. 11-21c, p. 237
![Page 81: Growth Responses and Regulation of Growth Chapter 11](https://reader033.vdocuments.us/reader033/viewer/2022051215/56649d145503460f949e9273/html5/thumbnails/81.jpg)
Turgor and TropismsTurgor and Tropisms
• Turgor movementsTurgor movements are temporary plant are temporary plant movementsmovements
• TropismsTropisms are permanent growth are permanent growth responses responses