Wednesday, September 5

1
Chapter 39Plant Responses to External and
Internal Signals
2
Chapter 39Plant Responses to External and
Internal Signals

• Getting from a signal to a response involves
  three steps
• Reception
• Transduction
• Response

3
Chapter 39Plant Responses to External and
Internal Signals

• Reception

Proteins change in response to specific stimuli
4
Chapter 39Plant Responses to External and
Internal Signals

• Reception

Proteins change in response to specific stimuli
5
Chapter 39Plant Responses to External and
Internal Signals

• Reception

Proteins change in response to specific stimuli
6
Chapter 39Plant Responses to External and
Internal Signals

• Reception

Proteins change in response to specific stimuli
7
Chapter 39Plant Responses to External and
Internal Signals

• Reception

Proteins change in response to specific stimuli
8
Chapter 39Plant Responses to External and
Internal Signals

• Reception

Proteins change in response to specific stimuli.
9
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
10
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
11
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
12
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
13
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
14
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
15
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
16
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
17
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
18
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
19
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
20
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
21
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
22
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
23
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
24
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
25
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
26
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
27
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
28
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
29
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
30
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
31
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
32
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
33
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
34
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals
35
Chapter 39Plant Responses to External and
Internal Signals

• Transduction

Second messengers transfer and amplify signals.
36
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
37
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
38
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
39
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
40
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
41
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
42
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
43
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
44
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
45
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
46
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
47
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
48
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
49
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
50
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
51
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
52
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
53
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes
54
Chapter 39Plant Responses to External and
Internal Signals

• Response

Activation of enzymes.
55
Chapter 39Plant Responses to External and
Internal Signals

• Plant Hormones

56
Chapter 39Plant Responses to External and
Internal Signals

• Plant Hormones
• Auxin
• Produced in apical meristem
• Stimulates cell elongation
• Causes phototropism.

57
Chapter 39Plant Responses to External and
Internal Signals

• Plant Hormones
• Cytokinins
• Produced in growing tissues
• Stimulates cell division.

58
Chapter 39Plant Responses to External and
Internal Signals

• Plant Hormones
• Gibberellins
• Stimulates growth in leaves and stems.

59
Chapter 39Plant Responses to External and
Internal Signals

• Plant Hormones
• Brassinosteroids
• Chemically similar to animal sex hormones
• Stimulates cell elongation and division.

60
Chapter 39Plant Responses to External and
Internal Signals

• Plant Hormones
• Abscisic acid
• Maintains dormancy in seeds.

61
Chapter 39Plant Responses to External and
Internal Signals

• Plant Hormones
• Ethylene
• Ripens fruit.

62
Chapter 39Plant Responses to External and
Internal Signals

• Plant Hormones
• Remember these two
• Auxin
• Ethylene

63
Chapter 39Plant Responses to External and
Internal Signals

• Responses to light

64
Chapter 39Plant Responses to External and
Internal Signals

• Responses to light
• Blue light is responsible for phototropism

65
Chapter 39Plant Responses to External and
Internal Signals

• Responses to light
• Blue light is responsible for phototropism
• Red light stimulates germination

66
Chapter 39Plant Responses to External and
Internal Signals

• Responses to light
• Blue light is responsible for phototropism
• Red light stimulates germination
• Far-red light inhibits germination and causes a
  plant to grow taller

67
Chapter 39Plant Responses to External and
Internal Signals

• Responses to light
• Blue light is responsible for phototropism
• Red light stimulates germination
• Far-red light inhibits germination and causes a
  plant to grow taller
• Why?

68
Chapter 39Plant Responses to External and
Internal Signals

• Biological Clocks

69
Chapter 39Plant Responses to External and
Internal Signals

• Biological Clocks
• Circadian rhythm is the 24-hour cycle of an
  organism

70
Chapter 39Plant Responses to External and
Internal Signals

• Biological Clocks
• Circadian rhythm is the 24-hour cycle of an
  organism.
• Photoperiodism is the physiological response to
  seasonal changes in light.

71
Chapter 39Plant Responses to External and
Internal Signals

• Photoperiodism
• Plants that bloom in fall or winter need short
  days to bloom

72
Chapter 39Plant Responses to External and
Internal Signals

• Photoperiodism
• Plants that bloom in fall or winter need short
  days to bloom
• Plants that bloom in spring or early summer need
  long days.

73
Chapter 39Plant Responses to External and
Internal Signals

• An experiment

74
Chapter 39Plant Responses to External and
Internal Signals

• An experiment

short day plants long day plants
75
Chapter 39Plant Responses to External and
Internal Signals

• An experiment

24 hours
short day plants long day plants
76
Chapter 39Plant Responses to External and
Internal Signals

• An experiment

short day plants long day plants
77
Chapter 39Plant Responses to External and
Internal Signals

• An experiment

short day plants long day plants
78

• What happens if we interrupt the night with a
  brief flash of light?

short day plants long day plants
79
Chapter 39Plant Responses to External and
Internal Signals
short day plants long day plants
80
Chapter 39Plant Responses to External and
Internal Signals

• Whats your conclusion?

short day plants long day plants
81
Chapter 39Plant Responses to External and
Internal Signals

• Another experiment

short day plants long day plants
82
Chapter 39Plant Responses to External and
Internal Signals

• Red light

short day plants long day plants
83
Chapter 39Plant Responses to External and
Internal Signals

• Red and far red

short day plants long day plants
84
Chapter 39Plant Responses to External and
Internal Signals

• Red, far red, red

short day plants long day plants
85
Chapter 39Plant Responses to External and
Internal Signals

• Red, far red, red, far red

short day plants long day plants
86
Chapter 39Plant Responses to External and
Internal Signals

• Conclusions?

short day plants long day plants
87
Chapter 39Plant Responses to External and
Internal Signals

• Other Stimuli
• Gravity (gravitropism)

88
Chapter 39Plant Responses to External and
Internal Signals

• Other Stimuli
• Gravity (gravitropism)

statoliths
89
Chapter 39Plant Responses to External and
Internal Signals

• Other Stimuli
• Gravity (gravitropism)

90
Chapter 39Plant Responses to External and
Internal Signals

• Other Stimuli
• Gravity (gravitropism)

91
Chapter 39Plant Responses to External and
Internal Signals

• Other Stimuli
• Gravity (gravitropism)

92
Chapter 39Plant Responses to External and
Internal Signals

• Other Stimuli
• Gravity (gravitropism)

93
Chapter 39Plant Responses to External and
Internal Signals

• Other Stimuli
• Gravity (gravitropism)

94
Chapter 39Plant Responses to External and
Internal Signals

• Other Stimuli
• Gravity (gravitropism)

95
Chapter 39Plant Responses to External and
Internal Signals

• Other Stimuli
• Gravity (gravitropism)
• Touch (thigmomorphogenesis and thigmotropism)

96
Chapter 39Plant Responses to External and
Internal Signals

• Other Stimuli
• Gravity (gravitropism)
• Touch (thigmomorphogenesis and thigmotropism)
• Environmental stresses.

97
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

98
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

99
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

100
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

101
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

102
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

103
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

chemical in saliva
wound
104
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

chemical in saliva
wound
signal transduction
105
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

chemical in saliva
wound
synthesis of volatile attractants
signal transduction
106
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

chemical in saliva
wound
synthesis of volatile attractants
signal transduction
107
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

chemical in saliva
wound
synthesis of volatile attractants
signal transduction
108
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

chemical in saliva
wound
synthesis of volatile attractants
signal transduction
109
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

chemical in saliva
wound
synthesis of volatile attractants
signal transduction
110
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

chemical in saliva
wound
synthesis of volatile attractants
signal transduction
111
Chapter 39Plant Responses to External and
Internal Signals

• Herbivores

chemical in saliva
wound
synthesis of volatile attractants
signal transduction
112
Chapter 39Plant Responses to External and
Internal Signals

• Pathogens

113
Chapter 39Plant Responses to External and
Internal Signals

• Pathogens

bacteria
114
Chapter 39Plant Responses to External and
Internal Signals

• Pathogens

bacteria
Plant recognizes specific pathogen
115
Chapter 39Plant Responses to External and
Internal Signals

• Pathogens

bacteria
Plant recognizes specific pathogen
Signal transduction
116
Chapter 39Plant Responses to External and
Internal Signals

• Pathogens

bacteria
Plant recognizes specific pathogen
Signal transduction
Diseased tissue is sealed off and killed
117
Chapter 39Plant Responses to External and
Internal Signals

• Pathogens

Plant recognizes specific pathogen
Signal transduction
Dying cells release salicylic acid
Diseased tissue is sealed off and killed
118
Chapter 39Plant Responses to External and
Internal Signals

• Pathogens

Plant recognizes specific pathogen
Signal transduction
Dying cells release salicylic acid
Diseased tissue is sealed off and killed
Systemic acquired resistance
Signal transduction
119
Chapter 39Plant Responses to External and
Internal Signals

• Any questions?
• .