Bos Jorunn I B, Armstrong Miles, Whisson Stephen C, Torto Trudy A, Ochwo Mildred, Birch Paul R J, Kamoun Sophien
Department of Plant Pathology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA.
Plant Pathogen Interaction Programme, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK.
New Phytol. 2003 Jul;159(1):63-72. doi: 10.1046/j.1469-8137.2003.00801.x.
Members of the oomycete genus Phytophthora cause some of the most devastating plant diseases in the world and are arguably the most destructive pathogens of dicot plants. Phytophthora research has entered the genomics era. Current genomic resources include expressed sequence tags from a variety of developmental and infection stages, as well as sequences of selected regions of Phytophthora genomes. Genomics promise to impact upon our understanding of the molecular basis of infection by Phytophthora, for example, by facilitating the isolation of genes encoding effector molecules with a role in virulence and avirulence. Based on prevalent models of plant-pathogen coevolution, some of these effectors, notably those with avirulence functions, are predicted to exhibit significant sequence variation within populations of the pathogen. This and other features were used to identify candidate avirulence genes from sequence databases. Here, we describe a strategy that combines data mining with intraspecific comparative genomics and functional analyses for the identification of novel avirulence genes from Phytophthora. This approach provides a rapid and efficient alternative to classical positional cloning strategies for identifying avirulence genes that match known resistance genes. In addition, this approach has the potential to uncover 'orphan' avirulence genes for which corresponding resistance genes have not previously been characterized.
疫霉属的成员引发了世界上一些最具毁灭性的植物病害，可以说是双子叶植物中最具破坏力的病原体。疫霉研究已进入基因组学时代。当前的基因组资源包括来自各种发育和感染阶段的表达序列标签，以及疫霉基因组选定区域的序列。基因组学有望影响我们对疫霉感染分子基础的理解，例如，通过促进分离在毒力和无毒力中起作用的效应分子编码基因。基于植物 - 病原体协同进化的普遍模型，预计其中一些效应分子，特别是那些具有无毒力功能的效应分子，在病原体种群中会表现出显著的序列变异。利用这一点和其他特征从序列数据库中鉴定候选无毒力基因。在这里，我们描述了一种将数据挖掘与种内比较基因组学和功能分析相结合的策略，用于从疫霉中鉴定新的无毒力基因。这种方法为鉴定与已知抗性基因匹配的无毒力基因提供了一种快速有效的替代传统定位克隆策略的方法。此外，这种方法有可能发现以前未鉴定出相应抗性基因的“孤儿”无毒力基因。
