Metabolic and structural rearrangement during dark-induced autophagy in soybean (Glycine max L.) nodules: an electron microscopy and 31P and 13C nuclear magnetic resonance study
Metabolic and structural rearrangement during dark-induced autophagy in soybean (Glycine max L.) nodules: an electron microscopy and 31P and 13C nuclear magnetic resonance study
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DOI：
10.1007/s00425-010-1148-3
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发表时间：
2010-04
期刊：
影响因子：
4.3
通讯作者：
P. Vauclare;R. Bligny;E. Gout;Valentine De Meuron;François Widmer
中科院分区：
文献类型：
--
作者：
P. Vauclare;R. Bligny;E. Gout;Valentine De Meuron;François Widmer
研究了暗胁迫对衰老大豆（Glycine maxL.）使用13 C-和31 P-NMR光谱法在体外分析结节。蔗糖和海藻糖是主要的可溶性碳源。在黑暗诱导的压力，糖和一些关键的糖酵解代谢产物的下降进行了观察。而84%的蔗糖消失，只有一半的海藻糖被利用。这种下降与谷氨酰胺，天冬酰胺，丙氨酸的消耗和酰脲的积累，这反映了一个巨大的减少N2固定。同时，磷酸二酯和化合物，如P-胆碱，膜磷脂水解和细胞自噬的良好标志物，积累在结节。细胞脂肪酸含量的减少证实了自噬过程。此外，观察到不饱和脂肪酸（油酸和亚油酸）略有增加，可能是对过氧化反应的反应。电子显微镜分析显示，尽管膜拆除，大多数类菌体似乎是结构完整的。综上所述，我们的研究结果表明，暗胁迫诱导的大豆碳水化合物饥饿引发了深刻的代谢和结构重排，在大豆根瘤的感染细胞，这是共生停止的代表。
The effects of dark-induced stress on the evolution of the soluble metabolites present in senescent soybean (Glycine maxL.) nodules were analysed in vitro using13C- and31P-NMR spectroscopy. Sucrose and trehalose were the predominant soluble storage carbons. During dark-induced stress, a decline in sugars and some key glycolytic metabolites was observed. Whereas 84% of the sucrose disappeared, only one-half of the trehalose was utilised. This decline coincides with the depletion of Gln, Asn, Ala and with an accumulation of ureides, which reflect a huge reduction of the N2fixation. Concomitantly, phosphodiesters and compounds like P-choline, a good marker of membrane phospholipids hydrolysis and cell autophagy, accumulated in the nodules. An autophagic process was confirmed by the decrease in cell fatty acid content. In addition, a slight increase in unsaturated fatty acids (oleic and linoleic acids) was observed, probably as a response to peroxidation reactions. Electron microscopy analysis revealed that, despite membranes dismantling, most of the bacteroids seem to be structurally intact. Taken together, our results show that the carbohydrate starvation induced in soybean by dark stress triggers a profound metabolic and structural rearrangement in the infected cells of soybean nodule which is representative of symbiotic cessation.