The long and the short of stomatal density signals

Recent studies have shown that environmental factors such as light and CO. are sensed by the mature leaves, which relay this information to developing leaves via long-distance systemic signals. The developing leaves respond by adjusting their stomatal density or stomatal index. These long-distance signals might interact with short-range signals that determine the density and patterning of stomata on the developing leaves. Clues to the nature of these interactions and the molecules involved, are bringing fresh understanding of the factors that regulate the density and patterning of stomata in response to environmental stimuli.