Plant Water Relations

Water underpins almost everything a plant does. Protoplasm itself is roughly 60-80% water, so a plant's whole structure - both externally and internally - depends on adequate water supply. Water is also the universal solvent in which most other substances that a plant needs are dissolved and transported, its high tensile strength is what makes the ascent of sap to great heights physically possible, and it plays a central role in regulating the plant's internal temperature and in maintaining the turgidity that keeps non-woody tissue firm and upright. Understanding how a plant gains, holds and moves this water - starting from simple imbibition, through water potential and osmotic behaviou …