Photosynthetic Oxygen Evolution at Low Water Potential in Leaf Discs Lacking an Epidermis

Photosynthesis without an epidermis

Water deficits inhibit photosynthesis but the contribution by metabolism and stomata is controversial. Tang et al. (pp. 861-870) removed an epidermis from leaf discs but a large inhibition remained, highlighting the importance of metabolism. The inhibition developed when the epidermis was absent during the water loss, eliminating the possibility that stomata close first and trigger the metabolic component.