Plant Growth

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Plant Growth

• Irreversible increase in size
• Increase in cell number
• Increase in dry weight
• Accomplished via

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Plant Growth

• Photosynthesis
• 6CO2 6H2O ---Light--- C6H12O6 6O2
• Respiration
• C6H12O6 6O2 ------ 6CO2 6H2O Energy in the
  form of ATP and NADPH

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Photosynthesis
4
Chloroplast
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Chloroplast
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Photosynthetic Reactions

• Light Reactions
• ATP and NADPH formed, O2 liberated
• Dark Reactions
• Calvin Cycle, C6H12O6 formed

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Light Reactions
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Dark Reactions
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Dark Reactions
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Light Dark Reactions
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Calvin Cycle
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Photosynthetic Action Spectrum
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Electromagnetic Spectrum
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Light Spectrum
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Factors Affecting Photosynthesis

• Light Quantity - Intensity
• Light Quality - Spectral Quality
• CO2 Levels
• Water
• Temperature-Biochemical Reactions
• Age of Plant Tissue

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Respiration

• The biological combustion of sugar.
• The process of creating energy for the machinery
  of the cell to run. (ATP, NADPH)
• Oxygen requiring process.

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Respiration

• C6H12O6 --------- 6CO2 6H2O Energy in form
  of ATP and NADP
• Aerobic-Process requires oxygen
• Anaerobic-If no O2, lactic acid ------
  fermentation

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Process of Respiration

• Biological combustion of sugar begins with the
  process known as Glycolysis.
• The by-products of glycolysis enter the Krebs
  Cycle where the majority of ATP energy is formed
  for the machinery of the cell to run.

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Glycolysis
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Glycolysis
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Krebs Cycle
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Krebs Cycle
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Electron Transport Chain
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Krebs Cycle Links

• http//www.sp.uconn.edu/terry/images/anim/ATPmito
  .html
• http//www.sp.uconn.edu/terry/images/anim/ETS.htm
  l
• http//www.sp.uconn.edu/terry/images/anim/protgra
  d.gif

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Plant Growth

• Photosynthesis - Build up of cells, tissues,
  organs.
• Respiration - Breakdown of sugars to provide
  energy for cell to run
• Metabolism
• Anabolism - build up
• Catabolism - breakdown

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An example of complex tissue is

• Cambium
• Xylem
• Parenchyma
• Sclerenchyma
• None of the above

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Living companion cells and sieve elements are
components of

• Xylem
• Phloem
• Cambium
• Meristem
• None of the above

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Dots on the apple are called

• Stomates
• Vetiphores
• Hydathodes
• Lenticels
• None of the above

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Water Uptake

• Root Pressure
• Transpirational Pull

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Factors involved in water uptake

• Root tissue
• Availability of water
• Salt levels in water
• Wind
• light

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Root Pressure
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Transpirational Pull

• Transpiration-loss of water in the form of vapor
  via stomates
• Continuous process in living plants as long as
  available water is supplied
• Will vary with light, wind speed and
  temperatures, etc.

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Plant Growth and Development

• Plant Life Cycles
• Annuals
• Biennials
• Perennials
• Monocarpic

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Seed Germination
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Seed Germination
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Plant Development

• Development occurs as a result of
• Genetic Base
• Environment and Adaptation
• Cellular Regulation
• Hormonal systems

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Plant Hormone Systems

• Auxin
• Cytokinin
• Gibberellin
• Ethylene
• Abscisic Acid

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Auxin

• Roles of Auxin
• Phototropism
• Apical Dominance
• Gravitropism
• Fruit Development
• Abscission
• Root Initiation

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Phototropism
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Auxin
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Auxin

• Synthetic
• IAA-Indole Acetic Acid
• Artificial
• IBA- Indole Butyric Acid
• NAA- Naphthalene Acetic Acid

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Auxin

• Artificial derivatives used in
• Rootone
• Hormex
• Hormodin

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Gibberellin

• Found in
• Leaf Primordia
• Seed Coat - Aleurone Layer
• Stems

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Gibberellin

• Roles
• Cell Elongation
• Eliminate Dwarfness
• Stimulate Male Flowers
• Overcome Dormancy in Seeds
• Overcome Cold Requirement for Some Plants

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Gibberellin
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Cytokinin

• Found in
• Developing fruits and seeds
• New shoots

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Cytokinin

• Roles
• Promotes shoot formation
• Promotes cell division

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Cytokinin

• Works with Auxin in tissue differentiation
• High Auxin, low Cytokinin-----Root Development
• Low Auxin, high Cytokinin----- Shoot
  Development
• Equal amounts------- Undifferentiated Tissue

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Cytokinin
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Abscisic Acid

• Inhibitor
• Found in
• Fruits
• Gelatinous parts of seeds
• Seed coats
• Abscission Layers

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Abscisic Acid

• Roles
• Seed Dormancy
• Prevent shoot growth
• Artificial Derivatives
• Bonzi
• Arest
• Chlormequat

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Abscisic Acid
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Ethylene

• Roles
• The ripening agent
• Promotes flowering
• Found in
• Ripening or maturing Tissue
• Occurs as a gas

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Ethylene
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Photoperiodism

• Response to day length
• Categories
• Short Day Daylengths less than 12 hrs.
• Long Day Daylengths longer than 12 hrs.

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Photoperiodism

• Phytochrome pigment involved in receiving light
  stimulus.

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Phytochrome Mechanism
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Photoperiodism

• Short Day Plants
• Chrysanthemum
• Poinsettia
• Cocklebur

• Long Day Plants
• Shasta Daisy
• Spinach
• Sugar Beets
• Radish

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Potted Chrysanthemum
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Poinsettia
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Shasta Daisy