期刊
NEW PHYTOLOGIST
卷 189, 期 1, 页码 135-147出版社
WILEY-BLACKWELL
DOI: 10.1111/j.1469-8137.2010.03449.x
关键词
cytosol; vacuole; hexose-P; in vivo nuclear magnetic resonance (NMR) spectroscopy; inorganic phosphate; intracellular pHs; plant cells; sugar starvation
资金
- UMR [5168]
- Institut de Recherche en Technologies et Sciences pour le Vivant, CEA-Grenoble
P>In plant cells, sugar starvation triggers a cascade of effects at the scale of 1-2 days. However, very early metabolic response has not yet been investigated. Soluble phosphorus (P) compounds and intracellular pHs were analysed each 2.5 min intervals in heterotrophic sycamore (Acer pseudoplatanus) cells using in vivo phosphorus nuclear magnetic resonance (31P-NMR). Upon external-sugar withdrawal, the glucose 6-P concentration dropped in the cytosol, but not in plastids. The released inorganic phosphate (Pi) accumulated transiently in the cytosol before influx into the vacuole; nucleotide triphosphate concentration doubled, intracellular pH increased and cell respiration decreased. It was deduced that the cytosolic free-sugar concentration was low, corresponding to only 0.5 mM sucrose in sugar-supplied cells. The release of sugar from the vacuole and from plastids is insufficient to fully sustain the cell metabolism during starvation, particularly in the very short term. Similarly to Pi-starvation, the cell's first response to sugar starvation occurs in the cytosol and is of a metabolic nature. Unlike the cytoplasm, cytosolic homeostasis is not maintained during starvation. The important metabolic changes following cytosolic sugar exhaustion deliver early endogenous signals that may contribute to trigger rescue metabolism.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据