Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH) CONICET/UNSAM, Chascomús, Argentina.
Mol Plant. 2011 Jan;4(1):127-43. doi: 10.1093/mp/ssq065. Epub 2010 Oct 26.
We characterized the transcriptomic response of transgenic plants carrying a mitochondrial dysfunction induced by the expression of the unedited form of the ATP synthase subunit 9. The u-ATP9 transgene driven by A9 and APETALA3 promoters induce mitochondrial dysfunction revealed by a decrease in both oxygen uptake and adenine nucleotides (ATP, ADP) levels without changes in the ATP/ADP ratio. Furthermore, we measured an increase in ROS accumulation and a decrease in glutathione and ascorbate levels with a concomitant oxidative stress response. The transcriptome analysis of young Arabidopsis flowers, validated by qRT-PCR and enzymatic or functional tests, showed dramatic changes in u-ATP9 plants. Both lines display a modification in the expression of various genes involved in carbon, lipid, and cell wall metabolism, suggesting that an important metabolic readjustment occurs in plants with a mitochondrial dysfunction. Interestingly, transcript levels involved in mitochondrial respiration, protein synthesis, and degradation are affected. Moreover, the levels of several mRNAs encoding for transcription factors and DNA binding proteins were also changed. Some of them are involved in stress and hormone responses, suggesting that several signaling pathways overlap. Indeed, the transcriptome data revealed that the mitochondrial dysfunction dramatically alters the expression of genes involved in signaling pathways, including those related to ethylene, absicic acid, and auxin signal transduction. Our data suggest that the mitochondrial dysfunction model used in this report may be useful to uncover the retrograde signaling mechanism between the nucleus and mitochondria in plant cells.
我们描述了携带由未编辑的 ATP 合酶亚基 9 表达引起的线粒体功能障碍的转基因植物的转录组反应。由 A9 和 APETALA3 启动子驱动的 u-ATP9 转基因导致线粒体功能障碍，表现为氧摄取和腺嘌呤核苷酸（ATP、ADP）水平降低，而 ATP/ADP 比值不变。此外，我们测量到 ROS 积累增加，谷胱甘肽和抗坏血酸水平降低，同时伴有氧化应激反应。通过 qRT-PCR 和酶或功能测试验证的年轻拟南芥花的转录组分析显示，u-ATP9 植物发生了显著变化。这两条系均显示出各种参与碳、脂质和细胞壁代谢的基因表达发生改变，表明线粒体功能障碍的植物发生了重要的代谢调整。有趣的是，涉及线粒体呼吸、蛋白质合成和降解的转录水平受到影响。此外，编码转录因子和 DNA 结合蛋白的几种 mRNA 的水平也发生了变化。其中一些与应激和激素反应有关，表明有几个信号通路重叠。事实上，转录组数据表明，线粒体功能障碍显著改变了参与信号通路的基因的表达，包括与乙烯、脱落酸和生长素信号转导相关的基因。我们的数据表明，本报告中使用的线粒体功能障碍模型可能有助于揭示植物细胞中核与线粒体之间的逆行信号机制。
