Transpiration
Transpiration can be regulated through stomatal closure or opening causing water to move out and evaporate on the leaf, while air flows in. It allows for plants to efficiently transport water up to their highest body organs, regulate the temperature of stem and leaves during heat-generating photosynthesis and it allows for upstream signaling such as the dispersal of an apoplastic alkalinization during local oxidative stress.
A very quick summary of this is:
- Soil
- Roots and Root Hair
- Xylem
- Leaves
- Air
Read more about this topic: Transpiration Stream