Chapter 10 Plant Anatomy Physiology Michael G Simpson

Chapter 10 Plant Anatomy & Physiology Michael G. Simpson Plant Anatomy Study of tissue and cell structure of plants. (In zoology, anatomy is study of internal organs; histology is study of tissues/cells. ) Plant Physiology Study of metabolic processes in plants.

Cell Theory All of life is composed of 1 or more cells. Cells arise only from pre-existing cells, via cell division or cell fusion. Cells are units of metabolic processes. Each cell contains set of hereditary information (DNA), transferred from cell to cell, coding for structural & functional features.

transport & modification storage high energy carbs. contains DNA structural support respiration cell recognition, transport photosynthesis protein synthesis & transport of materials ribosomes: site of protein synthesis storage: pigments, acids, ergastic substances

Ergastic Substances: not actively metabolized (storage/waste) aleurone grains: protein chromoplasts druses oil bodies amyloplasts (starch grains): alpha-1, 4 -glucopyranoside raphides crystals (Ca-oxalate; silica) styloids prismatics

cell wall mainly cellulose: beta-1, 4 -glucopyranoside

lignin - secondary cell wall function?

meristem - region of actively dividing cells 1) apical (shoot & root); 2) lateral (vascular & cork cambia) Cell differentiation: 1) Cell expansion (elongation) 2) Cell maturation / specialization

Plant Tissues & Cell Types Tissue: = group of cells with common function or structure. Three broad tissue types: 1) Dermal - outside layer(s) 2) Vascular - conduction 3) Ground - between dermal and vascular Simple vs. Complex Tissue: 1 versus 2 or more cell types

Ground Tissue Parenchyma: Gen. metabol. 1) Isodiametric to elongate 2) Primary cell wall 3) Living Collenchyma: support 1) Elongate 2) Primary cell wall thick, uneven, rich in pectins 3) Living

Ground Tissue Sclerenchyma 1) Secondary cell wall (+ primary) 2) Dead at maturity (usually) Fibers Elongate, sharply tapering

Ground Tissue Sclerenchyma 1) Secondary cell wall (+ primary) 2) Dead at maturity (usually) Sclereids Isodiametric to irregular

Vascular Tissue Xylem Water & mineral conduction Tracheary elements + parenchyma + sclerenchyma Phloem Sugar conduction Sieve members + parenchyma + sclerenchyma - Both complex tissues

Tracheary Elements Tracheids - Imperforate Vessels - Perforate Angiosperms (most) Gnetales A few Monilophytes

Sieve Elements Sieve cells - No sieve plates Sieve tube members - Sieve plates Apomorphy of Angiosperms

Dermal & Secretory tissues & cells Epidermis Glands Stomates Nectaries Laticifers

Dermal tissues: Trichome anatomy Epidermis

root cap ROOT (l. s. ) 1) Protective root cap 2) Absorptive root hairs root apical meristem

ROOT (c. s. ) 3) Give rise to new roots endogenously (from within)

Casparian Strip Function: forces fluids from outside through plasma membrane = selective absorption

SPOROPHYTIC SHOOT

Stems: • Give rise to leaves exogenously • Do not have a protective “cap” of cells • Do not have root hairs (but may have trichomes)

Stelar types eustele atactostele

Protoxylem maturation

Vascular cambium - a lateral meristem

Conifers: non-porous

Ring porous Diffuse porous

Wood Ray Anatomy

Leaf anatomy

Stomata

C 3 Photosynthesis

Kranz anatomy

C 4 Photosynthesis

CAM photosynthesis