3.12 - Mineral Requirements
Mineral ions and deficiency symptoms
- Plants take up mineral ions from the soil, and need them in the right amounts to stay healthy and grow.
- Two ions matter here: nitrate ions and magnesium ions.
What each ion is used for
- Nitrate ions - Provide nitrogen, which the plant uses to make amino acids. These are joined together to build proteins, which are needed for growth.
- Magnesium ions - Used to make chlorophyll, the green pigment in the chloroplasts that absorbs light for photosynthesis.
Deficiency symptoms
A shortage of either ion damages the plant in ways that show in how it looks and grows:
- Nitrate deficiency - Causes stunted growth, because the plant can't make the proteins it needs to build new tissue.
- Magnesium deficiency - Causes chlorosis: the leaves turn yellow, because the plant can't make enough chlorophyll to keep them green.
TermDefinition
ChlorosisThe yellowing of leaves caused by a lack of chlorophyll.
Deficiency symptomA visible sign in a plant that it is not getting enough of a particular mineral ion.