Metal in Soils and Uptake by Plants

Question 1

Why do soybean plants turn yellow?

Answer 1

Improper balance of minerals, specifically lack of Fe

Question 2

To be available for uptake by a plant, a mineral must be?

Answer 2

soluble

Question 3

Under high pH conditions, most Fe is bound to?

Answer 3

Soil particles

Question 4

What are the two tasks that proteins in the plant roots can do?

Answer 4

• Produce H+ to lower soil pH
• Help change Fe3+ to Fe2+

Question 5

Cadmium accumulation in browse vegetation, Alaska. Implications for Animal Health.

Answer 5

These authors studied Cd transport and uptake by the grayleaf willow, and measured Cd concentrations in soils overlying igneous and metamorphic rocks

Question 6

Results of Alaskan study:

Answer 6

1) Cd in the soils comes from wind-blown dust, not mining activities
2) Cd in soils was higher than that of the underlying rocks
3) The soils were acidic (4.5-6), so Cd should be mobile for plants
4) The Cd concentration of twigs and leaves from the grayleaf willow were 10x higher than those of other shrubs and moss
- Found that white-tailed ptarmigan who eat more grayleaf willow buds have a higher incidence of kidney damage
- Cd poisoning amongst other willow-feeding herbivores may be more widespread than previously suspected

Question 7

Molybdenosis leading to Type II Diabetes Mellitus in Swedish Moose

Answer 7

• About 150-180 affected animals reported annually = “Moose Wasting Disease”

Question 8

Symptoms of Moose Wasting Disease

Answer 8

• Diarrhea
• Emaciation
• Loss of appetite
• Apathy
• Osteoporosis
• Corneal opacity
• Lesions in GI tract
• Dilated heart

Question 9

After a necropsy study of the affected moose, it was found:

Answer 9

1) High lvls of Mo and low lvls of Cu in organ tissues
2) Elevated glucose concentrations (hyperglycemia)

Question 10

Mo is an essential trace element that controls the metabolism of Cu in ruminants

Answer 10

• Cu-deficiency is known to cause imbalances in the hypothalamus, which in turn can cause deficiency in sex hormones, which are necessary for proper regulation of glucose lvls
• 1st study to show a link b/w elevated Mo in the environment and the dev of diabetes in moose

Question 11

Hyperaccumulator Plants

Answer 11

• Several hundred hyperaccumulator plants have been discovered
• These unusual plants have the capacity to naturally accumulate high concentrations of certain elements, ie. Co, Ni, Cd, Pb, Zn, in their biomass
• Agromining: farming these plants as metal crops and harvesting their metal-rich biomass (enables access to resources not accessible by conventional mining and abundant low-grade sources of valuable elements)

Question 12

Alpine Pennycress

Answer 12

• Can absorb 1500ppm of Cd, whereas a normal plant would be poisoned at lvls of 20-50ppm
• Accumulates Cd and Zn without regulation
  0 Can increase metal solubility in the soil surrounding the root -> contributes to increased uptake
• 1 of 3 spp known to hyperaccumulate Cd, and only one known to hyperaccumulate Cd and Zn
• Could be harvested, burned, and the ashes sold as a source of Cd or Zn

Question 13

7 Organisms that can clean toxic waste

Answer 13

1) Oyster mushrooms
2) Sunflowers
3) Bivalves
4) Bonfire moss
5) Alpine pennycress
6) Tobacco
7) Greater Wax Moth

Question 14

Oyster Mushrooms

Answer 14

oil, hydrocarbons

Question 15

Sunflowers

Answer 15

radioactive isotopes

Question 16

Bivalves

Answer 16

pharmaceuticals, weed killers, antibacterials, triblocarbon

Question 17

Bonfire moss

Answer 17

Pb

Question 18

Alpine pennycress

Answer 18

Cd and Zn

Question 19

Tobacco

Answer 19

TNT, explosives

Question 20

Greater Wax Moth

Answer 20

plastic