Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, 38106 Braunschweig, Germany.
Genes (Basel). 2019 Apr 21;10(4):310. doi: 10.3390/genes10040310.
Plants are exposed to diverse abiotic and biotic stimuli. These require fast and specific integrated responses. Such responses are coordinated at the protein and transcript levels and are incorporated into larger regulatory networks. Here, we focus on the evolution of transcriptional regulatory networks involved in plant-pathogen interactions. We discuss the evolution of regulatory networks and their role in fine-tuning plant defense responses. Based on the observation that many of the cornerstones of immune signaling in angiosperms are also present in streptophyte algae, it is likely that some regulatory components also predate the origin of land plants. The degree of functional conservation of many of these ancient components has not been elucidated. However, ongoing functional analyses in bryophytes show that some components are conserved. Hence, some of these regulatory components and how they are wired may also trace back to the last common ancestor of land plants or earlier. Of course, an understanding of the similarities and differences during the evolution of plant defense networks cannot ignore the lineage-specific coevolution between plants and their pathogens. In this review, we specifically focus on the small RNA regulatory networks involved in fine-tuning of the strength and timing of defense responses and highlight examples of pathogen exploitation of the host RNA silencing system. These examples illustrate well how pathogens frequently target gene regulation and thereby alter immune responses on a larger scale. That this is effective is demonstrated by the diversity of pathogens from distinct kingdoms capable of manipulating the same gene regulatory networks, such as the RNA silencing machinery.
植物暴露于多种非生物和生物刺激下。这些需要快速和特定的综合反应。这些反应在蛋白质和转录水平上得到协调，并被纳入更大的调控网络中。在这里，我们专注于参与植物-病原体相互作用的转录调控网络的进化。我们讨论了调控网络的进化及其在微调植物防御反应中的作用。基于观察到被子植物免疫信号转导的许多基石也存在于石松藻类中，因此一些调控成分可能也早于陆地植物的起源。这些古老成分的许多功能保守程度尚未阐明。然而，苔藓植物的功能分析表明，一些成分是保守的。因此，这些调控成分中的一些以及它们的连接方式也可能追溯到陆地植物或更早的共同祖先。当然，在植物防御网络进化过程中，要理解相似性和差异性，不能忽视植物与其病原体之间的谱系特异性共同进化。在这篇综述中，我们特别关注涉及精细调控防御反应强度和时间的小 RNA 调控网络，并强调了病原体利用宿主 RNA 沉默系统的例子。这些例子很好地说明了病原体如何经常靶向基因调控，从而在更大范围内改变免疫反应。这种有效性体现在不同王国的病原体能够操纵相同的基因调控网络，如 RNA 沉默机制上。
