文章基本信息

标题：Effective use of high CO₂ efflux at the soil surface in a tropical understory plant
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作者：Atsushi Ishida ; Takashi Nakano ; Minaco Adachi 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
DOI：10.1038/srep08991
出版社：Springer Nature
摘要：Many terrestrial plants are C₃ plants that evolved in the Mesozoic Era when atmospheric CO₂ concentrations ([CO₂]) were high. Given current conditions, C₃ plants can no longer benefit from high ambient [CO₂]. Kaempferia marginata Carey is a unique understory ginger plant in the tropical dry forests of Thailand. The plant has two large flat leaves that spread on the soil surface. We found a large difference in [CO₂] between the partly closed space between the soil surface and the leaves (638 µmol mol⁻¹) and the atmosphere at 20 cm above ground level (412 µmol mol⁻¹). This finding indicates that the plants capture CO₂ efflux from the soil. Almost all of the stomata are located on the abaxial leaf surface. When ambient air [CO₂] was experimentally increased from 400 to 600 μmol mol⁻¹, net photosynthetic rates increased by 45 to 48% under near light-saturated conditions. No significant increase was observed under low light conditions. These data demonstrate that the unique leaf structure enhances carbon gain by trapping soil CO₂ efflux at stomatal sites under relatively high light conditions, suggesting that ambient air [CO₂] can serve as an important selective agent for terrestrial C₃ plants.