Department of Botany, Duke University, Durham, North Carolina 27706.
Plant Physiol. 1983 Oct;73(2):517-20. doi: 10.1104/pp.73.2.517.
(13)C nuclear magnetic resonance spectroscopy of intact leaves of Kalanchoë tubiflora was used to observe Crassulacean acid metabolism in vivo. (13)C signals from C-4 of malate were observed after overnight exposure of leaves to (13)CO(2). Illumination of the labeled leaves resulted in a gradual decrease in the malate signals. After a period of darkness in normal air, (13)C signals were detected in all four carbons of malate in the previously labeled leaves. The (13)C nuclear magnetic resonance spectrum of malate in solution was pH dependent, which allowed an estimation of the vacuolar pH from the whole leaf spectrum. The pH was 4.0 following a 14-hour dark period, but rose to greater than 6.0 after 6 hours of illumination.
采用(13)C 核磁共振光谱法对长寿花的完整叶片进行研究,以观察活体中的景天酸代谢。将叶片在(13)CO2 中暴露过夜后,可观察到来自苹果酸 C-4 的(13)C 信号。标记叶片的光照导致苹果酸信号逐渐减少。在正常空气中黑暗一段时间后,先前标记的叶片中苹果酸的四个碳原子均检测到(13)C 信号。苹果酸在溶液中的(13)C 核磁共振光谱对 pH 值具有依赖性,这使得可以从整个叶片光谱中估计液泡 pH 值。经过 14 小时的黑暗期后,pH 值为 4.0,但在 6 小时的光照后上升到大于 6.0。