Driever Steven M, Baker Neil R
Centre for Crop System Analysis, Wageningen University and Research, Wageningen, The Netherlands.
School of Biological Sciences, University of Essex, Colchester, UK.
Methods Mol Biol. 2018;1770:141-154. doi: 10.1007/978-1-4939-7786-4_9.
Oxygen is both product and substrate of photosynthesis and metabolism in plants, by oxygen evolution through water splitting and uptake by photorespiration and respiration. It is important to investigate these processes simultaneously in leaves, especially in response to environmental variables, such as light and temperature. To distinguish between processes that evolve or take up O in leaves in the light, in vivo gas exchange of stable isotopes of oxygen and membrane inlet mass spectrometry is used. A closed-cuvette system for gas exchange of leaf disks is described, using the stable isotopes O and O, with a semipermeable membrane gas inlet and isotope mass separation and detection by mass spectrometry. Measurement of evolution and uptake, as well as CO uptake, at a range of light levels allows composition of a light-response curve, here described for French bean and maize leaf disks.
氧气既是植物光合作用和新陈代谢的产物，也是底物，通过水的光解产生氧气，并通过光呼吸和呼吸作用吸收氧气。同时研究叶片中的这些过程非常重要，尤其是研究它们对光照和温度等环境变量的响应。为了区分光照下叶片中产生或吸收氧气的过程，采用了氧稳定同位素的体内气体交换和膜进样质谱法。本文描述了一种用于叶盘气体交换的封闭比色皿系统，该系统使用稳定同位素氧-16和氧-18，带有半透膜气体入口，通过质谱法进行同位素质量分离和检测。在一系列光照水平下测量氧气的产生和吸收以及二氧化碳的吸收，从而绘制光响应曲线，本文给出了菜豆和玉米叶盘的光响应曲线。
