State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403 1st Avenue South, Lethbridge, Alberta T1J 4B1, Canada.
Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403 1st Avenue South, Lethbridge, Alberta T1J 4B1, Canada.
Mol Plant. 2014 Dec;7(12):1740-55. doi: 10.1093/mp/ssu112. Epub 2014 Oct 20.
The first seedling or all-stage resistance (R) R gene against stripe rust isolated from Moro wheat (Triticum aestivum L.) using a map-based cloning approach was identified as Yr10. Clone 4B of this gene encodes a highly evolutionary-conserved and unique CC-NBS-LRR sequence. Clone 4E, a homolog of Yr10, but lacking transcription start site (TSS) and putative TATA-box and CAAT-box, is likely a non-expressed pseudogene. Clones 4B and 4E are 84% identical and divergent in the intron and the LRR domain. Gene silencing and transgenesis were used in conjunction with inoculation with differentially avirulent and virulent stripe rust strains to demonstrate Yr10 functionality. The Yr10 CC-NBS-LRR sequence is unique among known CC-NBS-LRR R genes in wheat but highly conserved homologs (E = 0.0) were identified in Aegilops tauschii and other monocots including Hordeum vulgare and Brachypodium distachyon. Related sequences were also identified in genomic databases of maize, rice, and in sorghum. This is the first report of a CC-NBS-LRR resistance gene in plants with limited homologies in its native host, but with numerous homologous R genes in related monocots that are either host or non-hosts for stripe rust. These results represent a unique example of gene evolution and dispersion across species.
利用基于图谱的克隆方法，从普通小麦（Triticum aestivum L.）中分离出第一个对条锈病具有全生育期抗性（R）的 R 基因 Yr10。该基因的 4B 克隆编码一个高度进化保守和独特的 CC-NBS-LRR 序列。Yr10 的同源物 4E 克隆，但缺乏转录起始位点（TSS）和假定的 TATA 框和 CAAT 框，可能是一个无表达的假基因。4B 和 4E 克隆在内含子和 LRR 结构域中具有 84%的同源性和分歧。基因沉默和转基因技术与接种具有不同毒力和无毒力条锈菌菌株相结合，证明了 Yr10 的功能。Yr10 的 CC-NBS-LRR 序列在小麦中已知的 CC-NBS-LRR R 基因中是独特的，但在 Aegilops tauschii 和其他单子叶植物中鉴定到高度保守的同源物（E = 0.0），包括大麦和短柄草。在玉米、水稻和高粱的基因组数据库中也鉴定到相关序列。这是第一个在其本地宿主中同源性有限的植物中鉴定到 CC-NBS-LRR 抗性基因的报告，但在相关单子叶植物中存在许多同源的 R 基因，这些基因是条锈菌的宿主或非宿主。这些结果代表了物种间基因进化和分散的独特范例。
