Apoplastic mesophyll signals induce rapid stomatal responses to CO2 in Commelina communis. Issue 2 (8th April 2013)

• Record Type: Journal Article
• Authors: Fujita, Takashi; Noguchi, Ko; Terashima, Ichiro
• Is Part Of: New phytologist. Volume 199:Issue 2(2013)
• Page Start: 395
• Page End: 406
• Publication Date: 2013-04-08
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.12261
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" xml:lang="en" id="nph12261-abs-0001"> <title>Summary</title> <p> <list id="nph12261-list-0001" list-type="bullet"> <list-item> <p>Previous studies have suggested that the mesophyll contributes to stomatal CO<sub>2</sub> responses.</p> </list-item> <list-item> <p>The effects of changes in CO<sub>2</sub> concentration (100 or 700 ppm) on stomatal responses in red or white light were examined microscopically in a leaf segment, an epidermal strip and an epidermal strip placed on a mesophyll segment of <italic>Commelina communis</italic>, all mounted on a buffer‐containing gel.</p> </list-item> <list-item> <p>In both red and white light, stomata of the leaf segment opened/closed rapidly at low/high CO<sub>2</sub>. In red light, epidermal strip stomata barely responded to CO<sub>2</sub>. In white light, they opened at low CO<sub>2</sub>, but hardly closed at high CO<sub>2</sub>. Stomata of the epidermal strip placed on the mesophyll responded in the same manner as those on the leaf segment. Insertion of a doughnut‐shaped cellophane spacer (but not polyethylene spacer) between the epidermal strip and the mesophyll hardly altered these responses. Stomata in leaf segments treated with 3‐(3, 4‐dichlorophenyl)‐1, 1‐dimethylurea (DCMU), a photosynthesis inhibitor, did not open in red light, but opened/closed at low/high CO<sub>2</sub> in white light.</p> </list-item> <list-item> <p>These results indicate that the apoplast transfer of 'mesophyll signals' and the stomatal opening at low CO<sub>2</sub> are dependent on photosynthesis, whereas the stomatal closure at high CO<sub>2</sub> is independent of photosynthesis.</p> </list-item> </list> </p> </abstract>