Phytopathology. 1998 Dec;88(12):1315-23. doi: 10.1094/PHYTO.1998.88.12.1315.
ABSTRACT The extracellular protein INF1 of Phytophthora infestans is a member of the elicitin family of protein elicitors known to induce a hypersensitive response on some solanaceous and cruciferous plants. The presence of INF1 elicitin in culture filtrates of 102 P. infestans isolates from 15 countries was examined. All tested isolates produced INF1 except five isolates collected in 1976 and 1977 from infected potatoes in East Germany (the former German Democratic Republic). Based on hybridization to the multi-locus DNA fingerprint probe RG57, all the INF1-nonproducing isolates were shown to belong to the clonal lineage US-1 that dominated world populations until the 1980s. Phylogenetic analysis of a set of European US-1 isolates using amplified fragment length polymorphism fingerprint data indicated that loss of INF1 production evolved independently in separate lineages within US-1. DNA and RNA blot hybridizations showed that INF1-nonproducing isolates still retain a copy of the inf1 gene, whereas little inf1 mRNA could be detected. Hypothetical interpretations of the evolution in a restricted geographic area of P. infestans lineages deficient in the production of a specific elicitor protein are discussed.
摘要 致病疫霉的胞外蛋白 INF1 是一种已知能够在一些茄科和十字花科植物上诱导过敏反应的蛋白激发子家族的成员。从 15 个国家的 102 个致病疫霉分离株的培养滤液中检测到了 INF1 激发子的存在。除了 1976 年和 1977 年从东德（前民主德国）受感染的土豆中采集的五个分离株外，所有测试的分离株都产生了 INF1。基于与多位点 DNA 指纹探针 RG57 的杂交，所有不产生 INF1 的分离株都属于 US-1 克隆谱系，该谱系在 20 世纪 80 年代之前主导着世界种群。使用扩增片段长度多态性指纹数据对一组欧洲 US-1 分离株进行的系统发育分析表明，在 US-1 内的不同谱系中，独立进化出了不产生 INF1 的现象。DNA 和 RNA 印迹杂交表明，不产生 INF1 的分离株仍然保留了 inf1 基因的一个拷贝，而很少能检测到 inf1 mRNA。本文讨论了在特定激发子蛋白产生受限的地理区域内，致病疫霉谱系进化的假设解释。
