13 ERA-CAP: Functional characterisation and validation of nonhost components in Triticeae species for durable resistance against fungal diseases

非寄主抗性（NHR）是植物所具有的最持久和广泛的抗性形式，可以抵御它们所处环境中经常发生的大多数病原体的攻击。为了在未来的作物保护概念中利用NHR，我们需要了解为什么少数适应性寄主病原体可以规避或抑制NHR，以及为了建立疾病，寄主植物的防御或调节相关蛋白、信号通路或结构成分是什么。在作物育种中快速利用NHR的一个主要障碍是NHR在物种水平上起作用，只有在特殊情况下，相应的抗性来源才能与相关作物杂交。因此，将非宿主抗性成分跨物种转移的基因技术方法是传统育种或分子育种的一个有吸引力的替代方法。在ERA-NET联盟TritNONHOST中，加上德国GABI计划（BMBF）资助的一些相关项目，我们在大麦和小麦中发现了许多与NHR相关的基因和遗传位点，这些基因和遗传位点与包括白粉病在内的三种主要真菌病原体相关。一组有限的受体样激酶在大麦和小麦的功能瞬时测定中成功验证，这将为DURESTrit联盟提出的工作提供重要的来源，此外还有来自野生大麦品种Hordeum bulbosum或来自NHR强度分离的实验大麦群体的抗性位点。在DURESTrit中，我们提出通过分别从野生大麦导入中产生和鉴定稳定的转基因和回交系，从功能上验证大麦和小麦中受体样激酶基因和有限数量的在宿主与非宿主相互作用中具有突出调节行为的基因。这些材料要么携带来自NHR供体的转基因基因或基因组片段，要么具有被RNAi沉默或使用TALEN技术进行基因修饰的潜在重要抗性成分。该项目将验证先前确定的强NHR候选物，特别强调受体样激酶，并确定通过广泛杂交或基因工程引入大麦或小麦的新NHR成分。这将加深我们对谷物中NHR的理解，并为通过转化研究开发NHR提供材料和技术。

Nonhost resistance (NHR) is the most durable and broadly acting form of resistance plants posses to ward off the majority of pathogen attacks regularly occurring within the environment they are living in. In order to exploit NHR in future crop protection concepts we need to understand why the minority of adapted host pathogens can circumvent or suppress NHR and what defense- or accommodation-related proteins, signalling pathways or structural components of their host plants are targeted in order to establish disease. A major obstacle to the rapid exploitation of NHR in crop breeding is related to the fact that NHR is operating at the species level, and only in exceptional cases corresponding sources of resistance can be crossed with related crop plants. Therefore, gene technological approaches to transfer nonhost-resistance components across species barriers are an attractive alternative to traditional or molecular breeding.In the ERA-NET consortium TritNONHOST, plus a number of related projects e.g. funded within the German GABI program (BMBF), we identified a number of genes and genetic loci in barley and wheat that are associated or correlated with NHR to three major fungal pathogens including powdery mildews. A limited set of those belonging to the group of receptor-like kinases were successfully validated in functional transient assays in barley and wheat and will provide an important source for the proposed work in the DURESTrit consortium, in addition to resistance loci derived from the wild barley species Hordeum bulbosum or from experimental barley populations segregating for NHR strength. In DURESTrit, we propose to functionally validate receptor-like kinase genes plus a limited number of genes with outstanding regulation behaviour in host- versus nonhost interactions both in barley and wheat by generating and characterizing stable transgenic and backcross lines from wild barley introgressions, respectively. These materials will either carry transgenes or genome fragments from NHR donors, or have potentially important resistance components silenced by RNAi or genetically modified using TALEN technology.The project will result in the validation of previously identified strong NHR candidates , with a special emphasis on receptor-like kinases, and in the identification of new NHR components introduced into barley or wheat by wide crosses or genetic engineering. This will deepen our understanding of NHR in cereals and provide materials and know-how for the exploitation of NHR by translational research.