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Adaxial/abaxial specification in the regulation of photosynthesis and stomatal opening with respect to light orientation and growth with CO 2 enrichment in the C 4 species Paspalum dilatatum
Author(s) -
Soares Ana Sofia,
Driscoll Simon P.,
Olmos Enrique,
Harbinson Jeremy,
Arrabaça Maria Celeste,
Foyer Christine H.
Publication year - 2008
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2007.02218.x
Subject(s) - photosynthesis , orientation (vector space) , botany , biology , chemistry , mathematics , geometry
Summary• Whole‐plant morphology, leaf structure and composition were studied together with the effects of light orientation on the dorso‐ventral regulation of photosynthesis and stomatal conductance in Paspalum dilatatum cv. Raki plants grown for 6 wk at either 350 or 700 µl l −1 CO 2 . • Plant biomass was doubled as a result of growth at high CO 2 and the shoot:root ratio was decreased. Stomatal density was increased in the leaves of the high CO 2 ‐grown plants, which had greater numbers of smaller stomata and more epidermal cells on the abaxial surface. • An asymmetric surface‐specific regulation of photosynthesis and stomatal conductance was observed with respect to light orientation. This was not caused by dorso‐ventral variations in leaf structure, the distribution of phospho enol pyruvate carboxylase (PEPC) and ribulose 1,5‐bisphosphate carboxylase/oxygenase (Rubisco) proteins or light absorptance, transmittance or reflectance. • Adaxial/abaxial specification in the regulation of photosynthesis results from differential sensitivity of stomatal opening to light orientation and fixed gradients of enzyme activation across the leaf.