The Metabolic Response of Arabidopsis Roots to Oxidative Stress is Distinct from that of Heterotrophic Cells in Culture and Highlights a Complex Relationship between the Levels of Transcripts, Metabolites, and Flux
The Metabolic Response of Arabidopsis Roots to Oxidative Stress is Distinct from that of Heterotrophic Cells in Culture and Highlights a Complex Relationship between the Levels of Transcripts, Metabolites, and Flux
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DOI：
10.1093/mp/ssn080
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发表时间：
2009-05-01
期刊：
影响因子：
27.5
通讯作者：
Laxa, Miriam
中科院分区：
文献类型：
--
作者：
Lehmann, Martin;Schwarzlaender, Markus;Laxa, Miriam
新陈代谢调节是植物对氧化胁迫反应的一个重要但知之甚少的部分。在之前的一项研究中(Baxter等人，2007年)，研究了培养中的拟南芥细胞对甲萘二酮诱导的氧化应激的代谢反应。发现了一种紧急生存策略，在这种策略中，合成代谢的初级代谢在很大程度上被下调，有利于分解代谢和抗氧化代谢。在整个植物组织中的反应可能是不同的，因此我们研究了拟南芥根对甲萘二酮处理的反应，分析了转录组、代谢组和关键代谢流，重点是初级代谢和次生代谢。使用对氧化还原敏感的绿色荧光蛋白，也表明甲萘二酮引起氧化还原扰动，不仅在线粒体中，而且在根的细胞质和质体中。在处理的前30min，反应类似于细胞培养：TCA循环和氨基酸生物合成的代谢物减少，转录反应以DNA调节蛋白上调为主。处理2 h和6 h后，根对细胞培养的反应不同。代谢物水平没有保持低迷，而是恢复了，在丙酮酸的情况下，一些氨基酸和脂肪族硫代葡萄糖苷显示出稳定的高于对照水平的增长。然而，没有观察到中枢碳代谢通量的重大变化，代谢转录物在很大程度上独立于相应的代谢物发生变化。综上所述，这些结果表明，根组织在氧化抑制后可以恢复代谢活性，并强调了糖酵解和氧化戊糖磷酸途径的潜在重要作用。
Metabolic adjustments are a significant, but poorly understood, part of the response of plants to oxidative stress. In a previous study (Baxter et al., 2007), the metabolic response of Arabidopsis cells in culture to induction of oxidative stress by menadione was characterized. An emergency survival strategy was uncovered in which anabolic primary metabolism was largely down-regulated in favour of catabolic and antioxidant metabolism. The response in whole plant tissues may be different and we have therefore investigated the response of Arabidopsis roots to menadione treatment, analyzing the transcriptome, metabolome and key metabolic fluxes with focus on primary as well as secondary metabolism. Using a redox-sensitive GFP, it was also shown that menadione causes redox perturbation, not just in the mitochondrion, but also in the cytosol and plastids of roots. In the first 30 min of treatment, the response was similar to the cell culture: there was a decrease in metabolites of the TCA cycle and amino acid biosynthesis and the transcriptomic response was dominated by up-regulation of DNA regulatory proteins. After 2 and 6 h of treatment, the response of the roots was different to the cell culture. Metabolite levels did not remain depressed, but instead recovered and, in the case of pyruvate, some amino acids and aliphatic glucosinolates showed a steady increase above control levels. However, no major changes in fluxes of central carbon metabolism were observed and metabolic transcripts changed largely independently of the corresponding metabolites. Together, the results suggest that root tissues can recover metabolic activity after oxidative inhibition and highlight potentially important roles for glycolysis and the oxidative pentose phosphate pathway.