Song Junqi, Bradeen James M, Naess S Kristine, Raasch John A, Wielgus Susan M, Haberlach Geraldine T, Liu Jia, Kuang Hanhui, Austin-Phillips Sandra, Buell C Robin, Helgeson John P, Jiang Jiming
Department of Horticulture, Biotechnology Center, University of Wisconsin, Madison, WI 53706, USA.
Proc Natl Acad Sci U S A. 2003 Aug 5;100(16):9128-33. doi: 10.1073/pnas.1533501100. Epub 2003 Jul 18.
Late blight, caused by the oomycete pathogen Phytophthora infestans, is the most devastating potato disease in the world. Control of late blight in the United States and other developed countries relies extensively on fungicide application. We previously demonstrated that the wild diploid potato species Solanum bulbocastanum is highly resistant to all known races of P. infestans. Potato germplasm derived from S. bulbocastanum has shown durable and effective resistance in the field. Here we report the cloning of the major resistance gene RB in S. bulbocastanum by using a map-based approach in combination with a long-range (LR)-PCR strategy. A cluster of four resistance genes of the CC-NBS-LRR (coiled coil-nucleotide binding site-Leu-rich repeat) class was found within the genetically mapped RB region. Transgenic plants containing a LR-PCR product of one of these four genes displayed broad spectrum late blight resistance. The cloned RB gene provides a new resource for developing late blight-resistant potato varieties. Our results also demonstrate that LR-PCR is a valuable approach to isolate genes that cannot be maintained in the bacterial artificial chromosome system.
晚疫病由卵菌病原体致病疫霉引起，是世界上最具毁灭性的马铃薯病害。在美国和其他发达国家，晚疫病的防治主要依赖于杀菌剂的使用。我们之前证明，野生二倍体马铃薯物种茄属植物对所有已知致病疫霉小种都具有高度抗性。源自茄属植物的马铃薯种质在田间已表现出持久而有效的抗性。在此，我们报告通过基于图谱的方法结合长片段（LR）-PCR策略克隆了茄属植物中的主要抗性基因RB。在遗传定位的RB区域内发现了一组四个CC-NBS-LRR（卷曲螺旋-核苷酸结合位点-富含亮氨酸重复序列）类抗性基因。含有这四个基因之一的LR-PCR产物的转基因植物表现出对晚疫病的广谱抗性。克隆的RB基因可为培育抗晚疫病马铃薯品种提供新资源。我们的结果还表明，LR-PCR是分离无法在细菌人工染色体系统中保存的基因的一种有价值的方法。
