The introgression of chromosome segments from wild relatives is an established strategy to enrich crop germplasm with disease-resistance genes¹. Here we use mutagenesis and transcriptome sequencing to clone the leaf rust resistance gene Lr9, which was introduced into bread wheat from the wild grass species Aegilops umbellulata². We established that Lr9 encodes an unusual tandem kinase fusion protein. Long-read sequencing of a wheat Lr9 introgression line and the putative Ae. umbellulata Lr9 donor enabled us to assemble the ~28.4-Mb Lr9 translocation and to identify the translocation breakpoint. We likewise cloned Lr58, which was reportedly introgressed from Aegilops triuncialis³, but has an identical coding sequence compared to Lr9. Cytogenetic and haplotype analyses corroborate that the two genes originate from the same translocation event. Our work sheds light on the emerging role of kinase fusion proteins in wheat disease resistance, expanding the repertoire of disease-resistance genes for breeding.

来自野生近缘种的染色体片段的渗入是用抗病基因丰富作物种质的既定策略¹。在这里，我们利用诱变和转录组测序克隆了叶锈病抗性基因Lr9，该基因是从野生草种Aegilops umbellulata ²引入面包小麦中的。我们确定Lr9编码一种不寻常的串联激酶融合蛋白。小麦Lr9基因渗入系和假定的Ae 的长读长测序。umbellulata Lr9供体使我们能够组装~28.4-Mb Lr9易位并识别易位断点。我们同样克隆了Lr58据报道，它是从Aegilops triuncialis ³基因渗入的，但与Lr9相比具有相同的编码序列。细胞遗传学和单倍型分析证实这两个基因源自同一易位事件。我们的工作揭示了激酶融合蛋白在小麦抗病性中的新兴作用，扩大了育种抗病基因库。