Meyer Jenelle D F, Silva Danielle C G, Yang Chunling, Pedley Kerry F, Zhang Chunquan, van de Mortel Martijn, Hill John H, Shoemaker Randy C, Abdelnoor Ricardo V, Whitham Steven A, Graham Michelle A
United States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011, USA.
Plant Physiol. 2009 May;150(1):295-307. doi: 10.1104/pp.108.134551. Epub 2009 Feb 27.
Asian soybean rust is a formidable threat to soybean (Glycine max) production in many areas of the world, including the United States. Only five sources of resistance have been identified (Resistance to Phakopsora pachyrhizi1 [Rpp1], Rpp2, Rpp3, Rpp4, and Rpp5). Rpp4 was previously identified in the resistant genotype PI459025B and mapped within 2 centimorgans of Satt288 on soybean chromosome 18 (linkage group G). Using simple sequence repeat markers, we developed a bacterial artificial chromosome contig for the Rpp4 locus in the susceptible cv Williams82 (Wm82). Sequencing within this region identified three Rpp4 candidate disease resistance genes (Rpp4C1-Rpp4C3 [Wm82]) with greatest similarity to the lettuce (Lactuca sativa) RGC2 family of coiled coil-nucleotide binding site-leucine rich repeat disease resistance genes. Constructs containing regions of the Wm82 Rpp4 candidate genes were used for virus-induced gene silencing experiments to silence resistance in PI459025B, confirming that orthologous genes confer resistance. Using primers developed from conserved sequences in the Wm82 Rpp4 candidate genes, we identified five Rpp4 candidate genes (Rpp4C1-Rpp4C5 [PI459025B]) from the resistant genotype. Additional markers developed from the Wm82 Rpp4 bacterial artificial chromosome contig further defined the region containing Rpp4 and eliminated Rpp4C1 (PI459025B) and Rpp4C3 (PI459025B) as candidate genes. Sequencing of reverse transcription-polymerase chain reaction products revealed that Rpp4C4 (PI459025B) was highly expressed in the resistant genotype, while expression of the other candidate genes was nearly undetectable. These data support Rpp4C4 (PI459025B) as the single candidate gene for Rpp4-mediated resistance to Asian soybean rust.
亚洲大豆锈病对包括美国在内的世界许多地区的大豆（Glycine max）生产构成了巨大威胁。目前仅鉴定出五个抗性来源（对大豆锈病菌1 [Rpp1]、Rpp2、Rpp3、Rpp4和Rpp5的抗性）。Rpp4先前在抗性基因型PI459025B中被鉴定出来，并定位在大豆18号染色体（连锁群G）上Satt288的2厘摩范围内。利用简单序列重复标记，我们为感病品种威廉姆斯82（Wm82）中的Rpp4基因座构建了一个细菌人工染色体重叠群。对该区域进行测序鉴定出三个Rpp4候选抗病基因（Rpp4C1 - Rpp4C3 [Wm82]），它们与莴苣（Lactuca sativa）的卷曲螺旋 - 核苷酸结合位点 - 富含亮氨酸重复序列抗病基因的RGC2家族具有最高的相似性。含有Wm82 Rpp4候选基因区域的构建体用于病毒诱导的基因沉默实验，以沉默PI459025B中的抗性，证实直系同源基因赋予抗性。利用从Wm82 Rpp4候选基因的保守序列开发的引物，我们从抗性基因型中鉴定出五个Rpp4候选基因（Rpp4C1 - Rpp4C5 [PI459025B]）。从Wm82 Rpp4细菌人工染色体重叠群开发的其他标记进一步界定了包含Rpp4的区域，并排除了Rpp4C1（PI459025B）和Rpp4C3（PI459025B）作为候选基因。逆转录 - 聚合酶链反应产物的测序显示，Rpp4C4（PI459025B）在抗性基因型中高度表达，而其他候选基因的表达几乎检测不到。这些数据支持Rpp4C4（PI459025B）作为Rpp4介导的对亚洲大豆锈病抗性的单一候选基因。
