1. Plant Functions BIOL 1407

2. Essential Nutrients Chemicals that organism cannot produce Must be acquired from environment Required to complete life cycle Photo Credit: BIOL 1407 Student, Austin Nature Center, Fall 2006

3. Macronutrients Large quantities –Carbon –Hydrogen –Oxygen –Nitrogen –Sulfur –Phosphorus –Potassium –Calcium –Magnesium Zea mays Vascular Bundle (Orange = Sclerenchyma) Photo Credit: Barnading, 2002, Wikimedia Commons

4. Micronutrients Tiny quantities Cofactors or components of enzyme systems

6. Source of Plant Nutrients Inorganic Compounds –Soil –Air

7. Transport Systems Why are they necessary?

8. Types of Transport Cell Transport –Across membrane Short-distance –Diffusion from cell to cell Long-distance –Bulk Flow –Down pressure gradients

9. Absorption of Water & Minerals From soil (most) Absorption –Diffusion –Osmosis –Facilitated Diffusion –Active Transport

10. Mineral Uptake: Cation Exchange Cations firmly bound to soil particles Roots secrete H + –Directly by H + pump –Indirectly by cellular respiration

11. Short-Distance Transport Lateral Transport –Symplast Pathway –Apoplast Pathway –Transmembrane Pathway

12. Short-Distance Transport in Roots

13. Long-Distance Transport Xylem –Water –Minerals Phloem –Organic compounds

14. Xylem

15. Xylem Transport Root Pressure Cohesion and Adhesion of Water in Xylem tubes Transpiration

16. Root Pressure Loading of water and minerals into xylem vessels  hydrostatic pressure in stele

17. Cohesion & Adhesion

18. Transpiration Evaporation of water from plant surfaces Mainly through leaf stomata

19. Transpiration Pull

23. Shoot Gas Exchange Leaves –Cuticle –Stomata – Opening –Guard Cells – Regulate Gas Exchange Stem –Lenticels Photo Credit of Lenticels: Sten Porse, 2007, Wikimedia Commons

24. Root Gas Exchange No cuticle No stomata

25. Phloem Transport Sugar Sources Sugar Sinks

26. Phloem Cells

27. Lateral Transport of Sugars

28. Apoplast Sieve tube element or companion cell

30. Phloem Transport

31. Plant Video http://www.youtube.com/watch?v=J1PqUB 7Tu3Yhttp://www.youtube.com/watch?v=J1PqUB 7Tu3Y

32. The End Unless otherwise specified, all images in this presentation came from: Campbell, et al. 2008. Biology, 8 th ed. Pearson Benjamin Cummings.