Troufflard Stéphanie, Roscher Albrecht, Thomasset Brigitte, Barbotin Jean-Noël, Rawsthorne Stephen, Portais Jean-Charles
Génie Enzymatique et Cellulaire, UMR-CNRS 6022, Université de Picardie Jules Verne, 33 Rue St-Leu, 80039 Amiens, France.
Phytochemistry. 2007 Aug-Sep;68(16-18):2341-50. doi: 10.1016/j.phytochem.2007.04.018. Epub 2007 May 30.
The dynamics of developing linseed embryo metabolism was investigated using (13)C-labelling experiments where the real-time kinetics of label incorporation into metabolites was monitored in situ using in vivo NMR. The approach took advantage of the occurrence in this plant tissue of large metabolite pools - such as sucrose or lipids - to provide direct and quantitative measurement of the evolution of the labelling state within central metabolism. As a pre-requisite for the use of steady state flux measurements it was shown that isotopic steady state was reached within 3 h at the level of central intermediates whereas it took a further 6h for the sucrose pool. Complete isotopic and metabolic steady state took 18 h to be reached. The data collected during the transient state where label was equilibrated but the metabolic steady state was incomplete, enabled the rates of lipid and sucrose synthesis to be measured in situ on the same sample. This approach is suitable to get a direct assessment of metabolic time-scales within living plant tissues and provides a valuable complement to steady state flux determinations.
利用¹³C标记实验研究了亚麻籽胚胎代谢的动态变化，在该实验中，使用体内核磁共振原位监测标记物掺入代谢物的实时动力学。该方法利用了这种植物组织中存在的大量代谢物库，如蔗糖或脂质，来直接定量测量中心代谢内标记状态的演变。作为使用稳态通量测量的先决条件，结果表明在中心中间体水平上3小时内达到同位素稳态，而蔗糖库则需要另外6小时。完全同位素和代谢稳态需要18小时才能达到。在标记物达到平衡但代谢稳态不完全的过渡状态期间收集的数据，使得能够在同一样品上原位测量脂质和蔗糖的合成速率。这种方法适用于直接评估活植物组织内的代谢时间尺度，并为稳态通量测定提供了有价值的补充。
