Université du Littoral Côte d'Opale, Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV-EA4492), Univ. Lille-Nord de France, GIS PhyNoPi, B.P.699, F-62229 Calais Cedex, France.
Université du Littoral Côte d'Opale, Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV-EA4492), Univ. Lille-Nord de France, GIS PhyNoPi, B.P.699, F-62229 Calais Cedex, France.
Plant Physiol Biochem. 2015 Nov;96:9-19. doi: 10.1016/j.plaphy.2015.07.015. Epub 2015 Jul 18.
Powdery mildew caused by Blumeria graminis f.sp. tritici, an obligate aerial biotrophic fungus, would be one of the most damaging wheat (Triticum aestivum) diseases without the extensive use of conventional fungicides. In our study, the expression levels of some basal defence-related genes were investigated during a compatible interaction in order to evaluate wheat reactions to infection, along with the different stages of the infectious process in planta. As fungal conidia initiated their germination and developed appressorial germ tube (AGT), early defence reactions involved the expression of a lipoxygenase (LOX)- and an oxalate oxidase (OXO)-encoding genes, followed by activations of corresponding LOX (EC 1.13.11.12) and OXO (EC 1.2.3.4) activities, respectively. When penetration of AGT took place, up-regulation of chitinases (CHI) and PR1-encoding genes expression occurred along with an increase of CHI (EC 3.2.1.14) activity. Meanwhile, expression of a phenylalanine ammonia-lyase-encoding gene also took place. Up-regulation of a phospholipase C- and lipid transfer proteins-encoding genes expression occurred during the latest stages of infection. Neither the phi glutathione S-transferase (GST)-encoding gene expression nor the GST (EC 2.5.1.13) activity was modified upon wheat infection by powdery mildew. Whether these defence reactions during such a compatible interaction are markers of immunity or susceptibility, and whether they have the ability to contribute to protection upon modulation of their timing and their intensity by resistance inducers are discussed.
由禾本科布氏白粉菌（Blumeria graminis f.sp. tritici）引起的白粉病是一种专性气生生物营养型真菌，如果不广泛使用传统杀菌剂，它将成为对小麦（Triticum aestivum）危害最大的病害之一。在本研究中，为了评估小麦对感染的反应以及感染过程在植物体内的不同阶段，研究了一些基础防御相关基因在亲和互作中的表达水平。当真菌分生孢子开始萌发并形成附着胞芽管（AGT）时，早期防御反应涉及脂氧合酶（LOX）和草酸盐氧化酶（OXO）编码基因的表达，随后分别激活相应的 LOX（EC 1.13.11.12）和 OXO（EC 1.2.3.4）活性。当 AGT 穿透时，几丁质酶（CHI）和 PR1 编码基因的表达上调，同时 CHI（EC 3.2.1.14）活性增加。同时，苯丙氨酸解氨酶编码基因的表达也上调。在感染的后期阶段，还上调了质膜 Ca2+-ATPase 和脂质转移蛋白编码基因的表达。感染白粉病后，phi 谷胱甘肽 S-转移酶（GST）编码基因的表达或 GST（EC 2.5.1.13）活性没有改变。在这种亲和互作中，这些防御反应是免疫还是易感性的标志物，以及它们是否有能力通过抗性诱导剂调节其时间和强度来促进保护，这些都有待讨论。
