Ding Bing-Bing, Zhang Yong-E, Yu Xin-Xiao, Jia Guo-Dong, Wang Yu-Song, Zheng Peng-Fei, Jiang Tao, Xia Juan-Juan
Ministry of Education Key Laboratory of Soil and Water Conservation and Desertification Combating, Beijing Forestry University, Beijing 100083, China.
Institute of Sediment Research, China Institute of Water Resources and Hydropower Research, Beijing 100038, China.
Ying Yong Sheng Tai Xue Bao. 2020 Jun;31(6):1800-1806. doi: 10.13287/j.1001-9332.202006.024.
Analysis of plant photosynthesis and post-photosynthetic fractionation can improve our understanding of plant physiology and water management. By measuring δC in the atmosphere, and δC of soluble compounds in leaves and branch phloem of Platycladus orientalis, we examined discrimination pattern, including atmosphere-leaf discrimination during photosynthesis (ΔC) and leaf-twig discrimination during post-photosynthesis (ΔC), in response to changes of soil water content (SWC) and atmospheric CO concentration (C). The results showed that ΔC reached a maximum of 13.06‰ at 95%-100% field water-holding capacity (FC) and C 400 μmol·mol, and a minimum of 8.63‰ at 35%-45% FC and C 800 μmol·mol. Both stomatal conductance and mesophyll cell conductance showed a significant linear positive correlation with ΔC, with a correlation coefficient of 0.43 and 0.44, respectively. ΔC was not affected by SWC and C. Our results provide mechanism of carbon isotopes fractionation and a theoretical basis for plant survival strategies in response to future climate change.
对植物光合作用和光合后分馏的分析可以增进我们对植物生理学和水分管理的理解。通过测量大气中的δC以及侧柏叶片和枝韧皮部中可溶性化合物的δC，我们研究了响应土壤含水量（SWC）和大气CO浓度（C）变化的分馏模式，包括光合作用期间的大气-叶片分馏（ΔC）和光合后期间的叶片-嫩枝分馏（ΔC）。结果表明，在田间持水量（FC）为95%-100%且C为400 μmol·mol时，ΔC最高达到13.06‰；在FC为35%-45%且C为800 μmol·mol时，ΔC最低达到8.63‰。气孔导度和叶肉细胞导度均与ΔC呈显著线性正相关，相关系数分别为0.43和0.44。ΔC不受SWC和C的影响。我们的结果提供了碳同位素分馏机制以及植物应对未来气候变化生存策略的理论基础。
