Normandie Université, UNIROUEN, Laboratoire Glyco-MEV EA 4358, Fédération de Recherche "Normandie Végétal" FED, Rouen, France.
INSERM U1239, Différenciation et Communication Neuronale et Neuroendocrine, Normandie Université, Rouen, France.
J Exp Bot. 2018 Aug 14;69(18):4235-4247. doi: 10.1093/jxb/ery238.
Extensins are cell wall glycoproteins, belonging to the hydroxyproline-rich glycoprotein (HRGP) family, which are involved in many biological functions, including plant growth and defence. Several reviews have described the involvement of HRGPs in plant immunity but little focus has been given specifically to cell wall extensins. Yet, a large set of recently published data indicates that extensins play an important role in plant protection, especially in root-microbe interactions. Here, we summarise the current knowledge on this topic and discuss the importance of extensins in root defence. We first provide an overview of the distribution of extensin epitopes recognised by different monoclonal antibodies among plants and discuss the relevance of some of these epitopes as markers of the root defence response. We also highlight the implication of extensins in different types of plant interactions elicited by either pathogenic or beneficial micro-organisms. We then present and discuss the specific importance of extensins in root secretions, as these glycoproteins are not only found in the cell walls but are also released into the root mucilage. Finally, we propose a model to illustrate the impact of cell wall extensin on root secretions.
伸展蛋白是细胞壁糖蛋白，属于富含羟脯氨酸的糖蛋白 (HRGP) 家族，参与许多生物学功能，包括植物生长和防御。已有几篇综述描述了 HRGPs 在植物免疫中的作用，但专门针对细胞壁伸展蛋白的研究较少。然而，大量新发表的数据表明，伸展蛋白在植物保护中起着重要作用，特别是在根-微生物相互作用中。在这里，我们总结了这一主题的最新知识，并讨论了伸展蛋白在根防御中的重要性。我们首先概述了不同单克隆抗体识别的伸展素表位在植物中的分布，并讨论了其中一些表位作为根防御反应标志物的相关性。我们还强调了伸展蛋白在由致病性或有益微生物引起的不同类型植物相互作用中的作用。然后，我们介绍并讨论了伸展蛋白在根分泌物中的特殊重要性，因为这些糖蛋白不仅存在于细胞壁中，而且还被释放到根粘液中。最后，我们提出了一个模型来说明细胞壁伸展蛋白对根分泌物的影响。
