Lecture # 6. OUTLINE : MINERAL NUTRITION
Apart from C, H, and O, all other nutrients are absorbed into land plants from the soil.
1. What are essential nutrients? Macronutrient, micronutrient
2. What chemical forms of the nutrients are available to the plant?
3. How does each nutrient enter the plant?
Gas: via stomates
Mineral nutrients or ions:
via roots
Via what type of transport mechanism? [later]
4. How do plants tolerate toxic heavy metals?
Cu, Zn, Cd, Pb.
5. What are the major function(s) of each nutrient?
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Essential nutrients are those nutrients which are necessary for a plant
to complete its life cycle, and for which no other element can substitute. Each
nutrient must have a clear function.
A. Amount required
Macronutrients (elements): C, H, O, N, K, Ca, Mg,
P, S
Micronutrient: Cl, Fe, B, Mn, Zn, Cu, Mo, Ni
B. Biochemical Functions
1) carbohydrates, lipids, Proteins, nucleic acids
CHO
CHO CHON(S) CHONP
2) Coenzyme: Mg, Ca, Mn, Zn,
Fe, Cu, Mo, Mn [redox rx]
3) Osmotic and electrical components: K+, Cl-,
H+, Ca2+
4) B function was unclear until recently: It crosslinks sugars in cell wall
pectins.
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Reading
1. Taiz & Zeiger 2006, 4th ed. ch.5. pp 73-84. Read summary on p. 91.
2. Taiz & Zeiger 2002, ch. 5
p. 67-82
Summary
p. (skip mycorrhizal fungi).
Read other parts for your interest and information.
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Lecture Review
1. Explain the difference between autotrophic and heterotrophic
growth.
2. What is meant by an "essential mineral nutrient"?
What is the difference between a macronutrient versus a micronutrient?
3. List the 17 elements that are essential for all plants.
Identify at least one structural role or metabolic role for each essential
element.
4. In what form(s) do C, O, and H enter the plant?
5. In what chemical form(s) do the following elements enter the
plant?
S, N, P, Cl