Why do plants store so much non-structural carbon?

Plants constantly risk desiccation because water spontaneously moves from high (plant) to low water potential (air). Cells must equilibrate their water potential to that of their surroundings to prevent water loss, and must lower it to acquire water. Stored non-structural carbon (NSC) could be critical for this dynamic regulation of water potential via continuous exchange of solutes. This role would explain why plants often store and maintain abundant NSC.