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Direct observation of reversible and irreversible stomatal responses of attached sunflower leaves to SO/sub 2/

Journal Article · · Plant Physiol.; (United States)
OSTI ID:5805348

The effects of SO/sub 2/ 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 SO/sub 2/. A distinction between uninjured and injured regions was clearly visible on leaves after exposure to 1.5 microliters per liter SO/sub 2/ for less than an hour. During the exposure, the mean value of apertures for many stomata, which indicates stomatal conductance and transpiration rate, tended to decrease simultaneously in the uninjured and injured regions. There was a good correlation between pore width and stomatal conductance measured with a porometer before exposure to SO/sub 2/. This correlation continued in leaves exposed to SO/sub 2/ until visible, irreversible injury occurred, but then it disappeared. The results of these experiments indicate the necessity of continuous observation of individual stomata under the microscope to understand the effects of air pollutants such as SO/sub 2/ on stomatal behavior.

Research Organization:
National Institute for Environmental Studies, Yatabe, Japan
OSTI ID:
5805348
Journal Information:
Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 79:1; ISSN PLPHA
Country of Publication:
United States
Language:
English