The metabolic response of heterotrophic Arabidopsis cells to oxidative stress
The metabolic response of heterotrophic Arabidopsis cells to oxidative stress
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DOI：
10.1104/pp.106.090431
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发表时间：
2007-01-01
期刊：
影响因子：
7.4
通讯作者：
Sweetlove, Lee J.
中科院分区：
文献类型：
--
作者：
Baxter, Charles J.;Redestig, Henning;Sweetlove, Lee J.
为了科普氧化胁迫，植物细胞的代谢网络必须重新配置，以绕过受损的酶或支持适应性反应。为了表征氧化应激过程中代谢变化的动力学，异养拟南芥（拟南芥）细胞用甲萘醌处理，并在6小时内采集的样品的时间序列中定量测定代谢产物丰度和C-13标记动力学的变化。氧化应激对中枢代谢途径产生了深远的影响，广泛的代谢抑制从三羧酸循环辐射，包括氨基酸代谢的大部门。特定途径中代谢物的连续积累表明糖酵解的后续备份和碳转移到氧化戊糖磷酸途径中。微阵列分析揭示了一种协调的转录组反应，这代表了一种紧急应对策略，允许细胞在代谢中断后存活。而不是试图取代抑制酶，转录编码这些酶实际上是下调，而抗氧化防御反应是安装。此外，从合成代谢到分解代谢的主要转变是有信号的。代谢也被重新配置，以绕过受损的步骤（e。G.诱导线粒体呼吸链的外部NADH脱氢酶）。拟南芥细胞对氧化胁迫的总体代谢反应与细菌和酵母（酿酒酵母）的超氧化物和过氧化氢刺激物非常相似，这表明植物和微生物的胁迫调节和信号传导途径可能具有共同的元素。
To cope with oxidative stress, the metabolic network of plant cells must be reconfigured either to bypass damaged enzymes or to support adaptive responses. To characterize the dynamics of metabolic change during oxidative stress, heterotrophic Arabidopsis (Arabidopsis thaliana) cells were treated with menadione and changes in metabolite abundance and C-13-labeling kinetics were quantified in a time series of samples taken over a 6 h period. Oxidative stress had a profound effect on the central metabolic pathways with extensive metabolic inhibition radiating from the tricarboxylic acid cycle and including large sectors of amino acid metabolism. Sequential accumulation of metabolites in specific pathways indicated a subsequent backing up of glycolysis and a diversion of carbon into the oxidative pentose phosphate pathway. Microarray analysis revealed a coordinated transcriptomic response that represents an emergency coping strategy allowing the cell to survive the metabolic hiatus. Rather than attempt to replace inhibited enzymes, transcripts encoding these enzymes are in fact down-regulated while an antioxidant defense response is mounted. In addition, a major switch from anabolic to catabolic metabolism is signaled. Metabolism is also reconfigured to bypass damaged steps (e. g. induction of an external NADH dehydrogenase of the mitochondrial respiratory chain). The overall metabolic response of Arabidopsis cells to oxidative stress is remarkably similar to the superoxide and hydrogen peroxide stimulons of bacteria and yeast (Saccharomyces cerevisiae), suggesting that the stress regulatory and signaling pathways of plants and microbes may share common elements.