Biology 172 Chapter 35 Plant Structure and Growth

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Biology 172Chapter 35Plant Structure and Growth
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Genes, the Environmentand Structure
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The Plant Body

• Shoot System
• Stems
• Leaves
• Root System
• Roots

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Tissue Systems
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Monocots vs. Dicots
Monocots
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The Root System

• Functions
• Anchorage
• Absorption
• Storage
• Origin
• Embryo
• Radicle
• Tap Root Systems
• Fibrous Root Systems
• Root Hairs
• Adventitious Roots

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Fibrous and Tap Root Systems
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Adventitious Roots/Root Hairs
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Stems

• Nodes
• Internodes
• Terminal Bud
• Axillary Bud
• Apical Dominance

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Axillary Buds
Petiole
Axillary Bud
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Modified Stems
Stolons
Rhizome
Tuber
Bulb
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Leaves

• Blade
• Petiole
• Veins
• Midrib

• Simple
• Compound
• Pinnately Compound
• Palmately Compound

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Types of Leaves
Simple Leaf Pinnately Palmately
Compound Compound
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LEAF VENATION
Parallel Venation
Pinnately Netted
Palmately Netted
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Modified Leaves
Tendrils
Spines
Succulent Leaves
Bracts
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GROUND TISSUES
Fiber

• Collenchyma
• Living
• Cell Wall Thickening
• Support
• Protection

• Sclerenchyma
• Non-Living
• Cell Walls
• Secondary Thickening
• Support

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Ground Tissues
Parenchyma
Collenchyma
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Epidermis - Leaf Cross Section
Dermal Tissues

• Epidermis
• Periderm
• Cork

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Dermal Tissues
Cork Periderm
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• Vascular Tissue
• Xylem Tracheids

Tracheids
Pits
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Xylem Vessels

• Xylem
• Vessels

Also contains parenchyma, colenchyma and fibers.
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Vascular Tissue PHLOEM
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Vascular Tissues
Sieve Tube Element
Companion Cell
Xylem Vessel
Air Space
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Meristemic Tissues

• Primary Growth
• Apical Meristem
• Roots
• Stems
• Intercalary Meristem
• Secondary Growth
• Lateral Meristems
• Vascular Cambium
• Cork Cambium

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Meristematic Tissues
Stem Tip
Apical Meristem
Procambium
Leaf Primordium
Ground Meristem
Bud Primordium
Procambium
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Root Tip
Apical Meristem
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Meristematic Tissues
Vascular Cambium
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Life Cycles

• Annuals
• Biennials
• Perennials

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Primary Growth in Roots
Meristem
Quiescent Zone
Root Cap
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Primary and Secondary Growth in Roots
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Primary Growth in Roots - Monocots
Cortex
Epidermis
Endodermis
Pericycle
Phloem
Xylem
Pith
Pith
Xylem Vessel
Casparian Strip
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Primary and Secondary Growth in Roots - Dicots
Endodermis Casparian Strip
Xylem
Vascular Cambium
Passage Cell
Pericycle
Phloem
Cortex
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Primary Growth in Stems
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EXTERNAL STEM ANATOMY
Terminal Bud
Axillary Bud
Internode
Node
Terminal Bud Scale Scar
Lenticel
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Primary and Secondary Growth in Stems
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Primary Growth in Stems
Bundle Sheath
Phloem Sieve Tube Element
Phloem Companion Cell
Xylem Vessel
Air Space
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Primary and Secondary Growth in Stems
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WOODY DICOT STEM
Summer Wood
Spring Wood
Phloem
Phloem Fibers
Cortex or Phloem Ray
Xylem Ray
Cork Cambium
Pith
Cork
Annual Ring
Primary Xylem
Secondary Xylem
Vascular Cambium
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Monocot Leaf - Zea
Guard Cells
Xylem
Stoma
Cuticle
Epidermis
Mesophyll
Phloem
Bundle sheath
Stoma
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INTERNAL LEAF ANATOMY DICOT
Upper Epidermis
Xylem
Palisade Mesophyll
Spongy Mesophyll
Lower Epidermis
Stomata and Guard Cells
Bundle Sheath
Phloem
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Dicot Leaf Cross Section
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Stomata
Guard Cells
Stoma
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Plant Growth and Development

• Common Genome
• Developmental Plasticity
• Environmental Impact
• Genetic
• Developmental Processes
• Growth Elongation
• Morphogenesis Dev. Body Form
• Differentiation Cell diversity Formation

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Molecular Evidence

• Genome Identity
• Arabidosis thaliana
• Smallest genome
• 26,000 Genes
• Fully Identified
• 45 Known
• Manipulation of Gene Expression

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Growth

• Involves Cell Division and Cell Expansion
• Plane and Symmetry
• Parallel Produces a Single File
• Random Unorganized Clump
• Asymmetrical Division May signal Key Events
  of Differentiation
• Preprophase Band of Microtubules
• Symmetrical All Cells Similar

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Cell Division
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Orientation of Cell Expansion

• Cortical Microtubule Arrangement
• May Regulate Cellulose Fibril Enzymes
• Organized Arrangement of Cellulose Microfibrils
• Expansion Perpendicular to Fibril Arrangement
• Enzymes to Break Fibril Cross Links
• Activated by H Secretion
• Arabidopsis fass Mutants
• No Preprophase Bands
• No Cortical Microtubules
• Unorganized Cellulose Microfibrils
• Expansion in all Direction

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Microfibrils and fass Mutant
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Morphogenesis

• Pattern Formation Dev of Specific
  Structures in Specific Locations
• Positional Information
• Polarity Longitudinal or Radial axes
• Position and Gene Expression
• Abnormal Gene Expression
• Homeotic Genes - KNOTTED-1
• Cellular Differentation
• Epidermal Cells and Root Hairs
• Cortical Cell Contact, 1 or 2
• GLABRA-2 gene

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Morphogenesis
Axial Polarity
Homeotic Genes
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Cell Differentiation
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Morphogenesis

• Phase Change
• Juvenile vs. Mature
• Meristem Identity Genes
• Vegetative vs. Floral
• Environmental, Hormonal
• Organ Identity Genes
• Positional
• ABC Hypothesis

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Phase Change
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Organ Identity Genes
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ABC Hypothesis