THE PHYSIOLOGY OF STOMATA: II. THE APPARENT ABSENCE OF CHLOROPHYLL, PHOTOSYNTHESIS, AND A NORMAL RESPONSE TO LIGHT IN THE STOMATAL CELLS OF AN ALBINO BARLEY

Publisher Website
Google Scholar
Abstract
The chlorophyll content of the pure albino plants produced by self-fertilizing a strain of variegated barley is about 1.2 μg. per gram fresh weight. The stomatal guard cells of the albino plants are normal in structure, but do not contain detectable amounts of chlorophyll. Microradioautography of epidermal strips previously exposed to radioactive carbon dioxide in light and darkness did not reveal the localization of radioactivity which would be expected in the guard cells if they were capable of photosynthesis. Moreover, the "albino" stomata do not open normally in response to light or in a carbon-dioxide-free atmosphere. These observations support the view that normal, light-sensitive stomatal cells contain functional chloroplasts and that stomatal opening is promoted by the photosynthetic removal of free carbon dioxide in the mesophyll and in the guard cells.