Institute of Evolution and the Department of Evolutionary and Environmental Biology, University of Haifa, 3498838, Haifa, Israel.
The Institute for Cereal Crops Improvement, Tel-Aviv University, 69978, Tel Aviv, Israel.
Theor Appl Genet. 2016 May;129(5):921-34. doi: 10.1007/s00122-016-2672-8. Epub 2016 Feb 5.
The wheat stripe rust resistance gene Yr36 ( WKS1 ) with a unique kinase-START domain architecture is highly conserved in wild emmer wheat natural populations. Wild emmer wheat (Triticum dicoccoides) populations have developed various resistance strategies against the stripe rust pathogen Puccinia striiformis f. sp. tritici (Pst). The wild emmer gene, Yr36 (WKS1), which confers partial resistance to a broad spectrum of Pst races, is composed of a kinase and a START lipid-binding domain, a unique gene architecture found only in the Triticeae tribe. The analysis of 435 wild emmer accessions from a broad range of natural habitats revealed that WKS1 and its paralogue WKS2 are present only in the southern distribution range of wild emmer in the Fertile Crescent, supporting the idea that wheat domestication occurred in the northern populations. An analysis of full-length WKS1 sequence from 54 accessions identified 15 different haplotypes and very low-nucleotide diversity (π = 0.00019). The high level of WKS1 sequence conservation among wild emmer populations is in contrast to the high level of diversity previously observed in NB-LRR genes (e.g., Lr10 and Pm3). This phenomenon may reflect the different resistance mechanisms and different evolutionary pathways that shaped these genes, and may shed light on the evolution of genes that confer partial resistance to stripe rust. Only five WKS1 coding sequence haplotypes were revealed among all tested accessions, encoding four different putative WKS1 proteins (designated P0, P1, P2, and P3). Infection tests showed that P0, P1, and P3 haplotypes display a resistance response, while P2 displayed a susceptible response. These results show that the WKS1 proteins (P0, P1, and P3) can be useful to improve wheat resistance to stripe rust.
小麦条锈病抗性基因 Yr36（WKS1）具有独特的激酶-起始域结构，在野生二粒小麦自然种群中高度保守。野生二粒小麦（Triticum dicoccoides）种群针对条锈病病原体条锈菌（Puccinia striiformis f. sp. tritici）（Pst）发展了各种抗性策略。赋予广谱 Pst 系部分抗性的野生二粒小麦基因 Yr36（WKS1）由一个激酶和一个 START 脂质结合结构域组成，这是一个独特的基因结构，仅在小麦族中发现。对来自广泛自然栖息地的 435 份野生二粒小麦材料的分析表明，WKS1 和其旁系 WKS2 仅存在于新月沃地的野生二粒小麦南部分布范围内，支持了小麦驯化发生在北部种群的观点。对来自 54 个材料的全长 WKS1 序列的分析确定了 15 个不同的单倍型和非常低的核苷酸多样性（π=0.00019）。野生二粒小麦群体中 WKS1 序列的高度保守与先前在 NB-LRR 基因（例如 Lr10 和 Pm3）中观察到的高度多样性形成鲜明对比。这种现象可能反映了塑造这些基因的不同抗性机制和不同进化途径，并可能为赋予条锈病部分抗性的基因的进化提供启示。在所有测试的材料中仅揭示了五个 WKS1 编码序列单倍型，编码四个不同的假定 WKS1 蛋白（指定为 P0、P1、P2 和 P3）。感染测试表明，P0、P1 和 P3 单倍型表现出抗性反应，而 P2 表现出易感性反应。这些结果表明，WKS1 蛋白（P0、P1 和 P3）可用于提高小麦对条锈病的抗性。
