Huang Xi, von Rad Uta, Durner Jörg
Institute of Biochemical Plant Pathology, GSF - National Research Center for Environment and Health, 85764 Oberschleissheim, Germany.
Planta. 2002 Oct;215(6):914-23. doi: 10.1007/s00425-002-0828-z. Epub 2002 Jul 25.
Nitric oxide (NO) is a double-edged sword - it can be either beneficial and activate defence responses in plants and animals or, together with reactive oxygen species, it can kill not only the pathogen but also the host. A prime target of NO is the cytochrome c-dependent respiration. Only plants possess alternative-pathway respiration with alternative oxidase (AOX) as a terminal electron acceptor. AOX has been suggested to be barely affected by NO. Here we show that NO affects cytochrome-dependent respiration in Arabidopsis thaliana (L.) Heynh. At the same time, treatment of Arabidopsis cell cultures with NO actually strongly induced AOX1a transcription, as determined by using a cDNA microarray and by Northern analysis. In accordance with transcript accumulation, NO treatment of suspension cells resulted in increased respiration through the alternative pathway. Addition of an AOX inhibitor to Arabidopsis cell cultures resulted in dramatically increased NO-sensitivity and cell death. In all, our data suggest that NO induces the AOX1a gene and that AOX may participate to counteract the toxicity of NO. Electronic supplementary material to this paper can be obtained by using the Springer Link server located at http://dx.doi.org/10.1007/s00425-002-0828-z.
一氧化氮（NO）是一把双刃剑——它既可以有益，激活动植物的防御反应，也可以与活性氧一起，不仅杀死病原体，还杀死宿主。NO的一个主要作用靶点是细胞色素c依赖性呼吸作用。只有植物拥有以交替氧化酶（AOX）作为末端电子受体的交替途径呼吸作用。有人认为AOX几乎不受NO影响。在此我们表明，NO影响拟南芥中的细胞色素依赖性呼吸作用。同时，正如通过使用cDNA微阵列和Northern分析所确定的，用NO处理拟南芥细胞培养物实际上强烈诱导了AOX1a转录。与转录积累一致，用NO处理悬浮细胞导致通过交替途径的呼吸作用增强。向拟南芥细胞培养物中添加AOX抑制剂导致NO敏感性显著增加和细胞死亡。总之，我们的数据表明NO诱导AOX1a基因，并且AOX可能参与对抗NO的毒性作用。本文的电子补充材料可通过位于http://dx.doi.org/10.1007/s00425-002-0828-z的Springer Link服务器获取。
