TAL effector nuclease (TALEN)-mediated generation of broad-spectrum powdery mildew resistant mlo plants

由Mildew Locus O（MLO）基因的功能丧失突变体等位基因赋予的持久广谱白粉病抗性是单子叶和双子叶植物中的保守现象。一些物种，遭受臭名昭著的白粉病，如玫瑰（罗莎spec.）或葡萄藤（葡萄属vinifera），由于各种原因（例如多倍性）不能很好地进行正向和/或反向遗传筛选以获得合适的mlo突变体。TAL效应核酸酶（TALEN）为基因的位点特异性诱变提供了新的工具，即使在复杂的真核基因组的背景下。在一项合作努力中，我们的目标是建立靶向MLO基因的TALEN，以产生定制的mlo功能丧失等位基因。将在充分建立mlo抗性分析的植物系统（大麦和拟南芥）中提供原理证明。接下来，TALEN将用于在玫瑰中产生抗白粉病的mlo突变体，玫瑰是一种迄今为止缺乏对抗白粉病的持久遗传资源的植物物种。拟议的研究不仅将为靶向产生抗白粉病植物突变体开辟新途径，还将为TALENs在精确基因组工程中的部署提供有价值的一般见解。

Durable broad-spectrum powdery mildew resistance conferred by loss-of-function mutant alleles of Mildew Locus O (MLO) genes is a conserved phenomenon in monocot and dicot plants. Some species that suffer notoriously from the powdery mildew disease, such as rose (Rosa spec.) or grapevine (Vitis vinifera), are for various reasons (e.g. polyploidy) not well accessible to forward and/or reverse genetic screens to obtain suitable mlo mutants. TAL effector nucleases (TALENs) provide a novel tool for site-specific mutagenesis of genes even within the context of complex eukaryotic genomes. In a collaborative effort we aim to establish TALENs that target MLO genes to generate tailor-made mlo loss-of-function alleles. Proof-of-principle will be provided in plant systems in which the analysis of mlo resistance is well established (barley and Arabidopsis thaliana). Next, TALENs will be used to generate powdery mildew resistant mlo mutants in rose, a plant species for which durable genetic resources to combat powdery mildew are lacking so far. The proposed research will not only open up new avenues for the targeted generation of powdery mildew resistant plant mutants but also provide valuable general insights for the deployment of TALENs in precision genome engineering.