The barley stem rust-resistance gene Rpg1 is a novel disease-resistance gene with homology to receptor kinases
The barley stem rust-resistance gene Rpg1 is a novel disease-resistance gene with homology to receptor kinases
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DOI：
10.1073/pnas.142284999
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发表时间：
2002-07-09
影响因子：
11.1
通讯作者：
Kleinhofs, A
中科院分区：
文献类型：
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作者：
Brueggeman, R;Rostoks, N;Kleinhofs, A
由小麦条锈病菌（Puccinia graminis f. sp. tritici）引起的秆锈病在1942年抗秆锈基因Rpg1应用之前，是美国和加拿大北部大平原大麦最具毁灭性的病害之一。从那时起，Rpg1为广泛种植的大麦品种提供了持久的保护，使其免受秆锈病造成的损失。通过与水稻的同线性来克隆Rpg1的大量努力提供了很好的侧翼标记，但未能得到该基因，因为它似乎在水稻中不存在。在此我们报道Rpg1基于图谱的克隆和特性分析。利用8518个配子构建的高分辨率遗传图谱以及一个330kb的细菌人工染色体重叠群物理图谱将该基因定位在两个交换点之间，相距约0.21厘摩和110kb。通过对低拷贝探针测序，在包含Rpg1的区域搜索潜在的候选基因。鉴定出两个类受体激酶基因。对来自抗病和感病品种的候选基因等位基因进行了测序。只有一个候选基因在抗病品种中显示出明显的功能性基因结构模式，而在感病品种中显示出有缺陷的基因结构模式，从而确定它为Rpg1基因。Rpg1编码一个具有两个串联蛋白激酶结构域的类受体激酶蛋白，这是一种植物抗病基因的新结构。因此，它可能代表一类新的植物抗病基因。
Stem rust caused by Puccinia graminis f. sp. tritici was among the most devastating diseases of barley in the northern Great Plains of the U.S. and Canada before the deployment of the stem rust-resistance gene Rpg1 in 1942. Since then, Rpg1 has provided durable protection against stem rust losses in widely grown barley cultivars (cvs.). Extensive efforts to clone Rpg1 by synteny with rice provided excellent flanking markers but failed to yield the gene because it does not seem to exist in rice. Here we report the map-based cloning and characterization of Rpg1. A high-resolution genetic map constructed with 8,518 gametes and a 330-kb bacterial artificial chromosome contig physical map positioned the gene between two crossovers approximate to0.21 centimorgan and 110 kb apart. The region including Rpg1 was searched for potential candidate genes by sequencing low-copy probes. Two receptor kinase-like genes were identified. The candidate gene alleles were sequenced from resistant and susceptible cvs. Only one of the candidate genes showed a pattern of apparently functional gene structure in the resistant cvs. and defective gene structure in the susceptible cvs. identifying it as the Rpg1 gene. Rpg1 encodes a receptor kinase-like protein with two tandem protein kinase domains, a novel structure for a plant disease-resistance gene. Thus, it may represent a new class of plant resistance genes.