Ye Zi Piao, Kang Hua Jing, Duan Shi Hua, Wang Yi Juan
College of Maths & Physics, Jinggangshan University, Ji'an 343009, Jiangxi, China.
Wenzhou Academy of Agricultural Sciences, Wenzhou 325006,Zhejiang, China.
Ying Yong Sheng Tai Xue Bao. 2018 Feb;29(2):583-591. doi: 10.13287/j.1001-9332.201802.025.
The availability of CO, a substrate for photosynthesis, affects the photosynthesis process and photosynthate production. Using the Li-6400-40B, we measured the photosynthetic electron transport rate and the photosynthetic light-response curves of soybean (Glycine max) leaves at different CO concentrations (300, 400, 500 and 600 μmol·mol). By fitting these parameters with a mechanistic model characterizing the light response of photosynthesis, we obtained aseries of photosynthetic parameters, eco-physiological parameters, as well as the physical parameters of photosynthetic pigments. The results showed that the electronic use efficiency, maximum electron transport rate, and maximum net photosynthetic rate increased with the increase of CO concentration. The light compensation point and dark respiration rate decreased with the increase of CO concentration. In addition, the light-use efficiency and intrinsic (instantaneous) water-use efficiency increased with the increase of CO concentration, and their values differed significantly among different CO concentrations. There was no significant difference on the maximum carboxylation efficiency among different CO concentrations. Those results suggested that CO concentration could affect the primary light reaction of photosynthesis in soybean leaves, and thus higher CO concentration could decrease the minimum average lifespan of excitons at the lowest excited state, which would enhance the velocity of light energy transport and the use efficiency of photosynthetic electron flow.
二氧化碳（CO）作为光合作用的一种底物，其可利用性会影响光合作用过程及光合产物的生成。我们使用Li-6400-40B在不同CO浓度（300、400、500和600 μmol·mol）下测量了大豆（Glycine max）叶片的光合电子传递速率和光合光响应曲线。通过用一个表征光合作用光响应的机理模型对这些参数进行拟合，我们获得了一系列光合参数、生态生理参数以及光合色素的物理参数。结果表明，电子利用效率、最大电子传递速率和最大净光合速率随CO浓度的增加而增加。光补偿点和暗呼吸速率随CO浓度的增加而降低。此外，光能利用效率和内在（瞬时）水分利用效率随CO浓度增加而增加，且在不同CO浓度下其值差异显著。不同CO浓度下最大羧化效率无显著差异。这些结果表明，CO浓度会影响大豆叶片光合作用的原初光反应，因此较高的CO浓度会降低最低激发态激子的最小平均寿命，这将提高光能传递速度和光合电子流的利用效率。
