Grün S, Lindermayr C, Sell S, Durner J
Institute for Biochemical Plant Pathology, GSF-Research Center for Environment and Health, Munich, Germany.
J Exp Bot. 2006;57(3):507-16. doi: 10.1093/jxb/erj053. Epub 2006 Jan 5.
There is increasing evidence that nitric oxide (NO), which was first identified as a unique diffusible molecular messenger in animals, plays an important role in diverse physiological processes in plants. Recent progress that has deepened our understanding of NO signalling functions in plants, with special emphasis on defence signalling, is discussed here. Several studies, based on plants with altered NO-levels, have recently provided genetic evidence for the importance of NO in gene induction. For a general overview of which gene expression levels are altered by NO, two studies, involving large-scale transcriptional analyses of Arabidopsis thaliana using custom-made or commercial DNA-microarrays, were performed. Furthermore, a comprehensive transcript profiling by cDNA-amplification fragment length polymorphism (AFLP) revealed a number of Arabidopsis thaliana genes that are involved in signal transduction, disease resistance and stress response, photosynthesis, cellular transport, and basic metabolism. In addition, NO affects the expression of numerous genes in other plant species such as tobacco or soybean. The NO-dependent intracellular signalling pathway(s) that lead to the activation or suppression of these genes have not yet been defined. Several lines of evidence point to an interrelationship between NO and salicylic acid (SA) in plant defence. Recent evidence suggests that NO also plays a role in the wounding/jasmonic acid (JA) signalling pathway. NO donors affect both wounding-induced H2O2 synthesis and wounding- or JA-induced expression of defence genes. One of the major challenges ahead is to determine how the correct specific response is evoked, despite shared use of the NO signal and, in some cases, its downstream second messengers.
越来越多的证据表明，一氧化氮（NO）最初被确定为动物体内一种独特的可扩散分子信使，在植物的多种生理过程中发挥着重要作用。本文讨论了最近的研究进展，这些进展加深了我们对植物中NO信号功能的理解，特别强调了防御信号。最近，几项基于NO水平改变的植物的研究为NO在基因诱导中的重要性提供了遗传学证据。为了全面了解哪些基因表达水平会被NO改变，进行了两项研究，它们使用定制或商业DNA微阵列对拟南芥进行大规模转录分析。此外，通过cDNA扩增片段长度多态性（AFLP）进行的全面转录谱分析揭示了许多参与信号转导、抗病性和应激反应、光合作用、细胞运输以及基础代谢的拟南芥基因。此外，NO还会影响烟草或大豆等其他植物物种中许多基因的表达。导致这些基因激活或抑制的NO依赖型细胞内信号通路尚未明确。有几条证据表明，在植物防御中，NO与水杨酸（SA）之间存在相互关系。最近的证据表明，NO在创伤/茉莉酸（JA）信号通路中也发挥作用。NO供体既影响创伤诱导的H2O2合成，也影响创伤或JA诱导的防御基因表达。未来面临的主要挑战之一是确定尽管共享NO信号，在某些情况下还共享其下游第二信使，但如何引发正确的特异性反应。
