While roots are important for absorbing nutrients from the soil, they don't actually store a specific nutrient like some other plant parts do.

Here's a breakdown:

* Roots absorb: Water, minerals (nitrogen, phosphorus, potassium, etc.), and sometimes trace elements.

* Roots don't store: Large quantities of a single nutrient.

* Other parts store nutrients: Fruits, seeds, stems, and leaves often store sugars, starches, proteins, or fats.

So, the answer to your question is: Roots don't primarily store a specific nutrient. They are the primary organs for absorbing nutrients from the soil.