Answer:
Cuticle
Explanation:
Plant cuticle is a waxy covering over the aerial epidermal cells of all the plants. Waxes are composed of cutin and a various organic solvent-soluble lipids. The cuticle is an extracellular hydrophobic layer which provides protection against desiccation and external environmental stresses. In other words the cucticle helps to retain water and give plants an adavanthe to live terrestrial life.
The hydroponics root system to grow is that they use the same method as the soil root but the root volume for hydroponics is highly restricted and they don't need to use too much energy to grow.
