Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Worringerweg 1, 52056 Aachen, Germany.
Mol Plant Microbe Interact. 2017 Mar;30(3):179-189. doi: 10.1094/MPMI-12-16-0255-CR. Epub 2017 Mar 30.
Loss-of-function mutations of one or more of the appropriate Mildew resistance locus o (Mlo) genes are an apparently reliable "weapon" to protect plants from infection by powdery mildew fungi, as they confer durable broad-spectrum resistance. Originally detected as a natural mutation in an Ethiopian barley landrace, this so-called mlo-based resistance has been successfully employed in European barley agriculture for nearly four decades. More recently, mlo-mediated resistance was discovered to be inducible in virtually every plant species of economic or scientific relevance. By now, mlo resistance has been found (as natural mutants) or generated (by induced mutagenesis, gene silencing, and targeted or nontargeted gene knock-out) in a broad range of monocotyledonous and dicotyledonous plant species. Here, we review features of mlo resistance in barley, discuss approaches to identify the appropriate Mlo gene targets to induce mlo-based resistance, and consider the issue of pleiotropic effects often associated with mlo-mediated immunity, which can harm plant yield and quality. We portray mlo-based resistance as an apparently universal and effective weapon to defeat powdery mildew disease in a multitude of plant species.
一个或多个适当的白粉病抗性基因座 O (Mlo) 基因的功能丧失突变，显然是一种保护植物免受白粉病真菌感染的可靠“武器”，因为它们赋予了广谱持久的抗性。最初在埃塞俄比亚大麦地方品种中发现的这种所谓的基于 mlo 的抗性，在近四十年的时间里已成功应用于欧洲大麦农业。最近，人们发现 mlo 介导的抗性在几乎每一种具有经济或科学重要性的植物物种中都是可诱导的。到目前为止，mlo 抗性已在广泛的单子叶和双子叶植物物种中被发现（作为自然突变体）或产生（通过诱导突变、基因沉默、靶向或非靶向基因敲除）。在这里，我们综述了大麦中 mlo 抗性的特征，讨论了鉴定适当的 Mlo 基因靶标以诱导基于 mlo 的抗性的方法，并考虑了与 mlo 介导的免疫相关的通常多效性效应的问题，这可能会损害植物的产量和质量。我们将基于 mlo 的抗性描绘为一种在多种植物物种中击败白粉病的通用且有效的武器。
