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Flashcards in Plant Nutrition Deck (22):
1

Source of plant nutrients

Dissolved nutrients in plant soil

2

Macronutrients

Main 3: C (CO2), O (CO2), H (H2O)
Rest: N (NO3- or NH4+; organic material), K (K+; rock minerals), Ca (Ca+2; rock minerals), Mg (Mg+2; rock minerals), P (H2PO4- or HPO4-2; organic material), S (SO4-2; organic material)

3

Micronutrients

Act as enzyme activators or cofactors
Come from minerals in soil
Cl, Fe, Mn, B, Zn, Cu, Ni, Mo

4

How to determine which nutrients are essential for plant growth

Control solution: solution containing all minerals
Experimental solution: solution without a certain mineral
See effects of lack of mineral on plant growth

5

Chlorosis

Lack of chlorophyll in a plant
Phosphate deficient: can see anthocyanin (purple color)
Potassium or nitrogen deficient: can see carotenoids (yellow-orange color)

6

Mobile nutrient

Can move in plant
Nitrogen deficient: can see in old leaves (nitrogen travels to new leaves)

7

Immobile nutrient

Cannot move in plant
Iron deficient: can see in young leaves (iron is confined to old leaves)

8

Epiphyte

Slow growing plant
Grows on other plants and symbiotically gains nutrients from them

9

Photosynthetic parasite

Taps into xylem of other plants
Limited nitrogen: high transpiration
Example: mistletoe

10

Carnivorous plants

Acidic soils with low nitrogen: make up for lack of nutrients by consuming other organisms (usually insects)
Example: pitcher plant

11

Components of soil

Water (25%)
Rock (45%)
Organic material (5%)
Air (25%)
Pore space: water and air

12

Tropical forest soil

Red in color (high iron content)
Deep (lots of weathering)
Organic material content low (lots of decomposition)

13

Prairie soil

Dark color
Not as deep
Lots of organic material: good for growing crops

14

Soil forming factors

"TROPC"
Time (younger soil-richer)
Relief (topography)
Organisms
Parent material (rock material that underlies soil)
Climate- temperature and rainfall

15

Cation exchange complex

Soil particles are negatively charged on the outside
Cations are attracted to the outside
Plant secretes H+ that displaces other cations, so they can be absorbed by the plant

16

Nitrogen fixation

Done by rhizobium (bacteria)
N2 + many ATP molecules -> NH3
Nitrogenase (enzyme secreted by rhizobium) catalyzes reaction
Leghemoglobin (iron-containing protein) regulates oxygen supply in reaction

17

Nitrogen cycle

Reactions mediated by bacteria
N2 or organic material -> NH3
NH3 + H+ (from soil) -> NH4+
NH4+ -> NO3- (absorbed by plant)
Leftover NO3- -> N2

18

Formation of nodules

Chemical signals from root attract bacteria, which cause infection thread
Bacteroids form from infection thread in root
Growth of bacteroids continues and a root nodule forms
Nodule develops vascular tissue

19

Mycorrhizae

Mutualistic relationship of fungus and plant
Increased surface area: increased absorption
Generally facultative
Can stimulate growth

20

Endomycorrhizae

Penetrate cell wall, but not plasma membrane
Corn, wheat

21

Ectomycorrhizae

Penetrate roots, but in between cell walls
Pine, oak, maple (truffels, morels)

22

Mantle

Fungal sheath formed by micorrhizae