Lines C E M, Ratcliffe R G, Rees T A V, Southon T E
Department of Plant Sciences, University of Oxford, Agricultural Science Building, Parks Road, Oxford, OX1 3PF, U.K.
New Phytol. 1989 Mar;111(3):447-456. doi: 10.1111/j.1469-8137.1989.tb00707.x.
C nuclear magnetic resonance (NMR) spectroscopy was applied to the lichen Xanthoria calcicola Oxner. The in vivo spectra were poorly resolved and although the line-broadening effect of variations in the bulk magnetic susceptibility could be eliminated by spinning the sample at the magic angle, the spectra were still relatively Uninformative in comparison with the spectra of methanol extracts of the tissue. The synthesis of ribitol by the algal symbiont and its subsequent metabolism to mannitol by the fungus was followed using pulse-chase experiments. The fine structure in the spectra provided support for the role of the pentose phosphate pathway in the conversion of ribitol to mannitol. Preliminary experiments, in which the conditions of the pulse-chase experiment were altered, showed that the incorporation of C into mannitol was reduced at a lower temperature, and in thalli of low moisture content, and was abolished by darkness.
将碳核磁共振（NMR）光谱法应用于地衣石黄衣（Xanthoria calcicola Oxner）。体内光谱的分辨率很差，尽管通过以魔角旋转样品可以消除体磁化率变化的线宽效应，但与组织甲醇提取物的光谱相比，这些光谱仍然相对缺乏信息。利用脉冲追踪实验追踪了藻类共生体合成核糖醇及其随后被真菌代谢为甘露醇的过程。光谱中的精细结构为戊糖磷酸途径在核糖醇转化为甘露醇中的作用提供了支持。改变脉冲追踪实验条件的初步实验表明，在较低温度下以及在低水分含量的叶状体中，碳掺入甘露醇的量减少，并且在黑暗中则完全停止。
