Direct Observation of Reversible and Irreversible Stomatal Responses of Attached Sunflower Leaves to SO2

Abstract
The effects of SO2 on stomatal aperture of attached sunflower leaves were observed with a remote-control light microscope system that permitted continuous observation of stomatal responses over periods of several hours. The relationship between actual stomatal aperture and stomatal conductance, measured with a porometer, also was examined on leaves before and after exposure to SO2.