Plant transport Chapter 36 Plant transport Evolutionary changes

Plant transport Evolutionary changes Roots, Leaves, Stems Water Carbohydrates Minerals Light energy CO 2

Water transport Roots Xylem Stomata Transpiration Cohesion & adhesion

Water transport Flaccid: Limp Water loss Plasmolysis: Cell membrane pulls away from cell wall

Water transport Turgid: Firm Water gain Healthier plant

Water transport Cell to cell (short distance) Diffusion Apolplast: Continuum formed by cell walls

Cell wall Apoplastic route Cytosol Symplastic route Transmembrane route Plasmodesma Plasma membrane Key Apoplast

Water transport Root hairs absorb water & minerals Diffuse into apoplast or symplast Pass

Casparian strip Plasma membrane Apoplastic route Symplastic route Vessels (xylem) Root hair Epidermis Endodermis

Xylem Movement based on bulk transport Transpiration: Negative pressure Root pressure: Positive pressure Upward

Xylem Guttation: Loss of liquid through leaves Ends of leaves Increased root pressure

Guard cells Opening & closing of the stomata Dependent on turgor pressure of guard

Guard cells Active K+ pump Increased K+ in the guard cells Increase in H

Carbohydrate movement Phloem (sieve-tube) Moves from source to nearest sink Carbohydrates enter sieve-tube cells

Carbohydrate movement Water potential differences-created Water moves into the sieve-tube cells (osmosis) Increased turgor

Carbohydrate movement Carbohydrates removed Active transport Water moves out (osmosis) Water diffuses back to

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Plant transport Chapter 36

Plant transport Evolutionary changes Roots, Leaves, Stems Water Carbohydrates Minerals Light energy CO 2

Water transport Roots Xylem Stomata Transpiration Cohesion & adhesion

Water transport Flaccid: Limp Water loss Plasmolysis: Cell membrane pulls away from cell wall Due to water loss

Water transport Turgid: Firm Water gain Healthier plant

Water transport Cell to cell (short distance) Diffusion Apolplast: Continuum formed by cell walls Symplast: Continuum formed by cytoplasm of cells Plasmodesmata: Connection between cytoplasm

Cell wall Apoplastic route Cytosol Symplastic route Transmembrane route Plasmodesma Plasma membrane Key Apoplast Symplast

Water transport Root hairs absorb water & minerals Diffuse into apoplast or symplast Pass through cortex Endodermis (inner lining of cortex) Casparian strip (waxy substance) Controls flow water/ions to xylem Forces flow to pass cell membrane

Casparian strip Plasma membrane Apoplastic route Symplastic route Vessels (xylem) Root hair Epidermis Endodermis Cortex Stele (vascular cylinder)

Xylem Movement based on bulk transport Transpiration: Negative pressure Root pressure: Positive pressure Upward push of water/ions in xylem Solar powered

Xylem Guttation: Loss of liquid through leaves Ends of leaves Increased root pressure

Stomata H 2 O loss CO 2 intake

Guard cells Opening & closing of the stomata Dependent on turgor pressure of guard cells Thicker inner cell layer Causes bowing of the cell when turgid Opens the stomata

Guard cells Active K+ pump Increased K+ in the guard cells Increase in H 2 O in the guard cells Turgid Stomata opens Decreased K+ leads to decreased H 2 O Flaccid, stomata closes

Translocation of Phloem Sap in Spring

Translocation of Phloem Sap in Summer

Carbohydrate movement Phloem (sieve-tube) Moves from source to nearest sink Carbohydrates enter sieve-tube cells Active transport Companion cells & parenchyma cells provide the ATP

Phloem

Carbohydrate movement Water potential differences-created Water moves into the sieve-tube cells (osmosis) Increased turgor Moves carbohydrates to sink

Carbohydrate movement Carbohydrates removed Active transport Water moves out (osmosis) Water diffuses back to xylem Or lost in transpiration