Growth and Development Phytochrome and Light Control

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Growth and DevelopmentPhytochrome and Light
Control

• Course BOT 331Plant Physiology
• February 27, 2009
• Pankaj Jaiswal
• Oregon State University
• Corvallis, OR

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Photomorphogenesis
In Dark In Light
In Dark In Light
Arabidopsis Seed Germination
Sunflower Seed Germination
Video Source Plants in Motion
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Phototropism
Maize Seedlings
Sunflower Seedlings
Video Source Plants in Motion
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Photomorphism FIG 17.2
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Absorption spectrum of purified Oat Pr and Pfr
FIG 17.3
Pr
Pfr
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Phytochrome induced responses FIG 17.4
Fluence Fluence rate/Irradiance Very Low Fluence
Rate (VLFR) Low Fluence Rate (LFR) High-irradiance
Response (HIR)
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Phytochrome FIG 17.7
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Phytochrome FIG 17.8
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Contribution of Phytochromes in Agronomy and
cellular processes
Germination of seeds Elongation of seedlings
(stem elongation) Size, shape and number of
leaves Plastid development Flowering time Set
Circadian Rhythms Anthocyanin production Orientati
on of chloroplast Leaf rolling/unrolling Leaf
development Shade avoidance Protein degradation
Corn Elm1 pictures Provided by Tom Brutnell _at_ BTI
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Role of Phytochromes in Signalling Pathways FIG
17.14
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Role of Phytochromes in Protein Degradation FIG
17.15
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Leaf Types
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Circadian Rhythm FIG 17.16
Video Source Plants in Motion
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Circadian Rhythm
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Leaves dropping in Mimosa (Touch-me-not)
Video source http//www.youtube.com/watch?v0o18U
USJgQA
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Ion fluxes between flexor and motor cells FIG
17.19
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Shade Avoidance Response FIG 17.22
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Role of LightThings to Remember

• Phytochrome Pr and Pfr
• Chromophore phytochromobilin and Aproprotein
• Change in protein state in Red Vs Far red light
• Roles in Agronomy
• Germination in red Vs far red light
• Fluence
• Irradiance/fluence rate
• Simple and compound leaves
• Flexor, motor cell and ion flux roles in leaf
  dropping