Can a plant be induced to accelerate transpiration? Just what the title states. I wonder whether it is possible to fire a chemical switch - sort-of like injecting adrenaline in a human, to accelerate a particular process in a plant. For example, transpiration.

With high(er) temperatures, especially in drier air with a bit of breeze, a plant will transpire more. While not a chemical solution, it is indeed a mechanism that serves to cool the plant.