1. Plant Transport

2. Transport Overview
Water and minerals
Sugars

3. Vascular Tissue Xylem Phloem Water Dissolved minerals Sugars
Amino acids
Hormones

4. Uptake of Minerals and Water
Lateral movement – soil to xylem
Diffusion and active transport of minerals
Increased surface area
Root hairs
Mycorrhizae
Symplastic and apoplastic movement
All minerals must pass through a selective membrane
Casparian strip prevents direct apoplastic movement into the xylem

5. Lateral Transport of Minerals and Water from Roots

6. Bulk Flow Transport Through Xylem
Root pressure – pushing water
Active transport of minerals into root creates lower water potential
Water enters cells and is pushed up xylem
Transpiration – pulling water
Water evaporates from leaves
Water pulled up xylem because of cohesion of water molecules
Transpiration controlled by openings in leaf called stoma

7. Transpiration

8. Control of Transpiration
Stoma open
K+ enter guard cell
Cell becomes turgid from influx of water
Stoma closed
K+ pumped out of guard cell
Cell becomes flaccid from efflux of water

9. Photorespiration Response to high heat and low water
Stoma close to prevent water loss causing low CO2 and high O2 levels in leaf
Carbon fixation low
Carbon is removed from RuBP to produce CO2
Rubisco runs in reverse

10. Loading of Sucrose into Phloem
Transport is in either direction at different times
Transport from sugar source to sugar sink
Sugar is pumped from source to sieve tube member

12. Mass Flow in a Sieve Tube