Signals from mature to new leaves

Stomata are microscopic pores on the surfaces of leaves, the number and density of which vary in response to changes in environmental conditions, such as carbon dioxide concentration and light. We show here that mature leaves of Arabidopsis thaliana detect and transmit this external information to new leaves of the same plant, producing an appropriate adjustment of stomatal development. As CO2 concentration controls both stomatal opening1 and number2,3, and stomatal numbers also increase with higher light intensity4, the large gradients of CO2 and light found within plant communities5 have the potential to influence stomatal development.