Plant Structure. Plant Organs Leaf Anatomy. Root Anatomy. Stem Anatomy. Plant Form. Shoot. Root. 1. What is a plant?

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1 Plant Structure Plant Form. What is a plant?. Meristems elaborate the plant body. Major Plant Organs: Morphology and anatomy Roots Stems Leaves. Tissues found in plants Ground Vascular Dermal Plant Organs Leaf Anatomy Shoot Root Stem Anatomy Root Anatomy

2 Cell Wall Apical Meristems. Shoot apical meristem forms o meristems Protoderm Procambium Ground meristem. Root apical meristem forms o meristems Protoderm Procambium Ground meristem Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Primary & Secondary Meristems. Primary Meristems Protoderm, protocambium & ground meristem Responsible for elongation growth Types Shoot primary meristem Root primary meristem Ground meristem Shoot Fig. Secondary 5.05a(TE Meristems Art) Apical meristem Protoderm Procambium. Secondary Meristem = Lateral meristem Responsible for diameter growth Types Vascular cambium Cork cambium Vascular cambium Cork cambium Lateral meristems Shoot Secondary Growth Shoot Secondary Growth Cork Cambium Annual Ring Vascular Cambium

3 Root Secondary Growth Primary Meristems Produce Tissue Systems Apical Meristem Primary Meristems Protoderm Dermal Tissue System Epidermis Trichomes Stomatal Complexes Ground Meristem Ground Tissue System Cortex Pith. Vascular cambium & o phloem. Secondary xylem Procambium Vascular Tissue System Xylem Phloem. Periderm. Cork and cork cambium Ground (Fundamental) Tissue System Components Collenchyma Sclerenchyma Characteristics Living cells Thin, primary cell wall Large vacuoles and thin band of cytoplasm Store starch, oils, tannins crystals Where is it found? Cortex of stems and roots Pith of stems Mesophyll of leaves Special types of parenchyma Chlorenchyma Aerenchyma Special types and functions of parenchyma Synthetic - mesophyll Meristematic apical meristems Secretory glands and nectaries Structural - aerenchyma Boundary - epidermis & endodermis Transport - transfer cells Aerenchyma in papyrus

4 Leaf & Root Specialized Palisade mesophyll (parenchyma) Spongy mesophyll (parenchyma) Root cortex (parenchyma) Aerenchyma in papyrus Collenchyma Collenchyma Living cytoplasm Unevenly thickened primary cell walls Usually just beneath the epidermis Function: flexible support Sclerenchyma Sclerenchyma Sclereids Characteristics of sclerenchyma Cells dead at maturity Thick secondary cell walls Lignified cell walls Types of sclerenchyma Sclereids or stone cells - isodiametric Fibers very long sclerenchyma cells Economic value: Ropes, string canvas

5 Sclerenchyma: Fibers. Xylem. Phloem Vascular Tissue Xylem: Tracheids and Vessel Members Xylem: Tracheids,Vessel Members & Perforation Plates Vessel - Perforation plates Simple Scalariform Reticulate Tracheid Imperforate cell = No perforation plate Tracheids Vessel Members Xylem Secondary Wall Architecture 5 Xylem: Bordered Pits Bordered Pit Xylem: Transverse section Xylem: Longitudinal section Types of Secondary Wall Thickenings in Xylem. Annular. Helical. Scalariform. Reticulate 5. Pitted 5

6 Vascular Tissue Phloem Xylem Phloem Fibers Phloem Cell Characteristics Phloem Anatomy Sieve elements Sieve cells Sieve tube members form sieve tubes Companion cells Phloem parenchyma Pores Phloem Dermal Tissue System Types of epidermal cells. Ordinary epidermal cells. Stomatal Complexes. Trichomes Dermal Tissue System - Ordinary Epidermal Cells Morphology: Wavy, elongated, tabular flattened Epidermis of Galium aparine leaf Epidermis of Zygochloa leaf (a grass) Tradescantia upper epidermis 6

7 Dermal Tissue System Epidermal Cell Characteristics Stomatal Complexes Epidermis of Tulipa leaf Oleander upper epidermis Guard cell expressing green fluorescent protein bound to talin, a protein that binds to actin filaments. Red/orange structures are chloroplasts.. Aglaophyton guard cells Trichomes Trichomes Mullein Leaf SEM Stomatal Apparatus Dermal Tissue System Cuticle END 7