Elevated CO2 concentration induces photosynthetic down-regulation with changes in leaf structure, non-structural carbohydrates and nitrogen content of soybean

作者：Yunpu Zheng, Fei Li, Lihua Hao, Jingjin Yu, Lili Guo, Haoran Zhou, Chao Ma, Xixi Zhang, Ming Xu · 发表于：BMC Plant Biology · 年份：2019 · DOI：10.1186/s12870-019-1788-9 · 被引用次数：143 · 研究领域：Plant responses to elevated CO2、Atmospheric chemistry and aerosols、Plant Water Relations and Carbon Dynamics

Understanding the mechanisms of crops in response to elevated CO 2 concentrations is pivotal to estimating the impacts of climate change on the global agricultural production. Based on earlier results of the “doubling-CO 2 concentration” experiments, many current climate models may overestimate the CO 2 fertilization effect on crops, and meanwhile, underestimate the potential impacts of future climate change on global agriculture ecosystem when the atmospheric CO 2 concentration goes beyond the optimal levels for crop growth. This study examined the photosynthetic response of soybean ( Glycine max (L.) Merr.) to elevated CO 2 concentration associated with changes in leaf structure, non-structural carbohydrates and nitrogen content with environmental growth chambers where the CO 2 concentration was controlled at 400, 600, 800, 1000, 1200, 1400, 1600 ppm. We found CO 2 -induced down-regulation of leaf photosynthesis as evidenced by the consistently declined leaf net photosynthetic rate ( A n ) with elevated CO 2 concentrations. This down-regulation of leaf photosynthesis was evident in biochemical and photochemical processes since the maximum carboxylation rate ( V cmax ) and the maximum electron transport rate ( J max ) were dramatically decreased at higher CO 2 concentrations exceeding their optimal values of about 600 ppm and 400 ppm, respectively. Moreover, the down-regulation of leaf photosynthesis at high CO 2 concentration was partially attributed to the reduced stomatal...