1. Plant nutrition
Chapter 37

2. Plant nutrition Roots: Absorb water & minerals from soil. Leaves:
CO2 diffuses from surrounding air through stomata.

3. Nutrients

4. Nutrients CO2 fixation in photosynthesis
H2O solvent, cell turgid, volume for cell elongation
Several inorganic nutrients
Organic substances majority of plant weight (sugars, cellulose)
O2 cellular respiration

5. Soil Soil horizons: Distinct soil layers Top soil most important
Loams:
Most fertile top soil
Supports most growth

6. Fig. 37-2
A horizon
B horizon
Figure 37.2 Soil horizons
C horizon

7. Soil Topsoil: Particles derived from rock (minerals) Living organisms
Humus:
Decaying matter
Bacteria, algae, fungi, insects, worms

8. Topsoil Inorganic: Cations (K, Ca, Mg) Cation exchange:
Exchange with H ions
Absorbed through root hairs
Anions (nitrate, sulfate, phosphate)

9. D:\Chapter_37\A_PowerPoint_Lectures\37_Lecture_Presentation\37_03MineralsFromSoil_A.html

10. Soil pH
Water

11. Cultivation
Depletes nutrients
Crop rotation
Fertilizers

12. Fig. 37-5
Figure 37.5 Contour tillage

13. Phytoremediation Process of removing contamination
Soil & water by plants
TCE (trichloroethylene) organic solvent
TNT (trinitrotoluene)
Heavy metals (Pb, Cd)

14. Nutrients Essential: Required nutrients Macronutrients
C, O, H, N, P, S
Components of organic substances
Ca, Mg, K
Micronutrients
Cofactors in enzymatic reactions

16. Nutritional deficiency
Symptoms of mineral deficiency
Magnesium deficiency (chlorophyll)
Causes yellowing of the leaves, or chlorosis
Iron deficiency
Cofactor in chlorophyll synthesis also causes chlorosis

17. Nutritional deficiency

18. Healthy Phosphate-deficient Potassium-deficient Nitrogen-deficient
Fig. 37-7
Healthy
Phosphate-deficient
Potassium-deficient
Figure 37.7 The most common mineral deficiencies, as seen in maize leaves
Nitrogen-deficient

19. Nutritional deficiency

20. Food Fortification Genetically modified plants
Absorb nutrients-human consumption
Breakfast cereals additional nutrients in the grains
Golden rice (vitamin A fortified)

21. Nitrogen Nitrogen makes proteins & nucleic acids
Atmospheric nitrogen is N2
Bacteria can “fix” nitrogen
Plants can absorb it
Bacteria live near roots or found in plant tissue

22. Nitrogen Rhizophere: Soil layer bound to roots Rhizobacteria:
Bacteria in the rhizophere

23. Nitrogen

24. Mycorrhizae Roots & fungi mutualistic relationship
Help absorb nutrients
Ectomycorrhizae
Fungi produces mantle
Arbuscular mycorrhizae
Penetrate root cells

25. Nutritional adaptations
Epiphyte:
Grows on another plant
Absorbs water and minerals from rain
Parasitic:
Absorb nutrients from plant host
Carnivores:
Obtain nitrogen and minerals from insects

26. Nutritional adaptations

27. Nutritional adaptations