Soares Ana Sofia, Driscoll Simon P, Olmos Enrique, Harbinson Jeremy, Arrabaça Maria Celeste, Foyer Christine H
Crop Performance and Improvement Division, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
Centro de Engenharia Biológica & Departamento de Biologia Vegetal, Faculdade de Ciências da Universidade de Lisboa, Campo Grande 1749-016 Lisboa, Portugal.
New Phytol. 2008;177(1):186-198. doi: 10.1111/j.1469-8137.2007.02218.x. Epub 2007 Sep 11.
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 microl 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 phosphoenolpyruvate 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.
研究了扩张雀稗（Paspalum dilatatum cv. Raki）植株的全株形态、叶片结构和组成，以及光照方向对其光合作用背腹调节和气孔导度的影响。这些植株在350或700 μl l⁻¹ CO₂浓度下生长6周。高浓度CO₂条件下生长使植株生物量增加了一倍，且茎根比降低。高浓度CO₂生长的植株叶片气孔密度增加，其叶片下表面气孔数量更多、气孔更小，表皮细胞更多。观察到光合作用和气孔导度在光照方向上存在不对称的表面特异性调节。这并非由叶片结构的背腹差异、磷酸烯醇式丙酮酸羧化酶（PEPC）和核酮糖-1,5-二磷酸羧化酶/加氧酶（Rubisco）蛋白的分布或光吸收、透射或反射引起。光合作用调节中的近轴/远轴特异性是由于气孔开放对光照方向的敏感性差异以及整个叶片上酶激活的固定梯度所致。
