Question

Manganese toxicity results in deficiency of iron, magnesium and calcium because:

• A. It competes with iron and magnesium for uptake and inhibits calcium translocation in the shoot apex
• B. It inhibits iron and calcium translocation and binding of magnesium with enzymes
• C. It competes with calcium and magnesium for uptake and inhibits iron translocation in the shoot apex
• D. It prevents the translocation of iron, magnesium, and calcium from roots to the shoot

Answer 1

The correct option is A

It competes with iron and magnesium for uptake and inhibits calcium translocation in the shoot apex

When an excess of manganese is present in the soil, it competes with iron and magnesium for uptake through the carrier proteins of root hair plasma membrane. Manganese tends to accumulate in shoot tips thus inhibiting the translocation of calcium to the shoot apices.