All plants require four things.
The first is sunlight, necessary for photosynthesis. Second, they need air, specifically carbon dioxide, which the plant converts into sugars, protein, and other building blocks through the energy derived from the sun. Lastly, plants need water for a variety of functions. Water absorbed by roots makes its way to the leaves where some of the water molecules are split during photosynthesis, releasing oxygen and energy. Water not used in photosynthesis cools leaves in a process known as transpiration.