1. paul.m.hasegawa.1@purdue.edu Mineral Nutrition Plant life cycle
#11- Plant Mineral Nutrition
HORT 301 – Plant Physiology
September 20, 2010
Taiz and Zeiger – Chapter 5, Chapter 12
Skotomorphogenesis
Seed germination
Hormones, signaling, genetic determinants
Embryo and
Seed development
Plant life cycle
Photomorphogenesis
Photoreceptors
Phytochrome
Structure and function of cells
Phytochrome: regulation of
light responses
Photosynthesis: light reaction
Photosynthesis: carbon fixation
Photorespiration
Primary & secondary metabolism
Respiration
Mineral Nutrition
Water

2. Plant Mineral Nutrition HORT 301 – Plant Physiology September 20, 2010
Taiz and Zeiger - Chapters 5 & 12
Plant mineral nutrition – essential elemental nutrients required by plants
courtesy of Burkhard Schulz

3. -K -Mg -Fe -N -Ca Essential mineral elements
Growth, development or completion of life cycle
Metabolism and plant structure -K
-Mg
-Fe -N
-Ca

4. Essential macronutrients and micronutrients
Macronutrient – up to 1.5%, 15,000 ppm in dry matter

5. Micronutrient - 100 ppm (dry matter) or less

6. Mineral nutrient classification based on biochemical function
Group 1 (N and S) – components of organic molecules
Group 2 (P, Si, B) – P- energy storage (ATP) or Si & B - cell wall structure

7. Group 3 (K, Ca, Mg, Cl, Mn, Na) – metabolism, enzyme co-factors, osmotic adjustment, signaling, structure

8. Group 4 (Fe, Zn, Cu, Ni, Mo) – metals involved in redox reactions (electron transfer)

9. Hydroponic culture – mineral nutrients, aeration, pH control

10. Mineral nutrient forms in soils and cellsK+
Ca2+
Cl-
P – H2PO4-
S – SO42-
N – NH4+ or NO3-

11. Mineral nutrient deficiency – Web Topic 5
Mineral nutrient deficiency – Web Topic 5.1 for typical deficiency symptoms – N, P, K, Ca
Epstein & Bloom Mineral Nutrition of Plants 2004

12. Mobile and immobile mineral elements and symptom development
Mobile - symptoms evident first in older leaves
Non-mobile – symptoms develop first in new leaves

13. Tissue mineral nutrient content – growth and yield
Critical concentration – minimum nutrient limited
Adequate zone – maximal growth and yield
Toxic zone – nutrient excess

14. Plant nutrition and soil pH – pH 7
Plant nutrition and soil pH – pH 7.0 is typically optimal for nutrient solubility and availability

15. Mineral nutrients in soils – weathering of soils and organic materials are sources
Soil properties affects availability in the soil solution for root absorption

16. Mineral nutrient absorption roots absorb mineral nutrients
Water and nutrient deprivation causes remodeling of root architecture to maximize root surface area (secondary roots and root hairs)
Hydrotropism – root capacity to sense water and grow toward the source

17. + - portion of root system receiving complete nutrient solution
Localized supply of PO4,2- , NO3- , NH4+ , or K+ and the architecture of barley root growth
+ - portion of root system receiving complete nutrient solution
- - Part of the root system receiving the solution deficient
in specified nutrient
Drew (1975) New Phytol. 75 :

18. Primary root structure and nutrient absorption – uptake may occur all along the root
Root hairs increase surface

19. Nutrient absorption by roots creates a depletion zone
Root or root hair growth increases access to soil solution that is not depleted of nutrients

20. Mycorrhiza (mycorrhizae) – root interaction – nutrient and water absorption
Mycorrhizal fungi - sugars, plants – mineral, nutrients and water
Ectomorphic mycorrhizal fungi – hyphae extend along apoplast of cortical cells
Arbuscular mycorrhizal fungi – hyphae penetrate into cortical cell symplast and branch (arbuscule)

21. Radial ion movement to the xylem
Transport to shoots in the transpiration stream

22. Xylem loading – transport from endodermal cells to xylem elements via xylem parenchyma cells
Transport proteins regulate ion transport into and out of the xylem
Ion movement from root to shoot in the transpiration stream

23. Mineral nutrient assimilation – incorporation into organic molecules
NH4+ or NO3-, SO42-, and H2PO42-
Sulfur – SO42- is a product of soil weathering
Uptake into roots via SO H+ symporter and translocated through the plant
SO42- - assimilated into cysteine

24. Phosphorous – HPO42- - uptake (PO42- -H+ symporter) and translocated form
Assimilated into ATP (ATP synthase), photosynthesis, oxidative phosphorylation (respiration)
Cation mineral nutrients (K, Ca, Mg, Fe, Mn, Cu, Co, Na, Zn) – function as ions or are in organic molecules via noncovalent bonds
Coordination bonds (several oxygen or nitrogen atoms share electrons) to form a bond with a cation nutrient, chlorophyll a

25. Electrostatic interactions – charge group attraction, e. g
Electrostatic interactions – charge group attraction, e.g., Ca2+ for carboxylate groups in pectin (Ca2+-pectate)