Torto-Alalibo Trudy A, Tripathy Sucheta, Smith Brian M, Arredondo Felipe D, Zhou Lecong, Li Hua, Chibucos Marcus C, Qutob Dinah, Gijzen Mark, Mao Chunhong, Sobral Bruno W S, Waugh Mark E, Mitchell Thomas K, Dean Ralph A, Tyler Brett M
Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Mol Plant Microbe Interact. 2007 Jul;20(7):781-93. doi: 10.1094/MPMI-20-7-0781.
Six unique expressed sequence tag (EST) libraries were generated from four developmental stages of Phytophthora sojae P6497. RNA was extracted from mycelia, swimming zoospores, germinating cysts, and soybean (Glycine max (L.) Merr.) cv. Harosoy tissues heavily infected with P. sojae. Three libraries were created from mycelia growing on defined medium, complex medium, and nutrient-limited medium. The 26,943 high-quality sequences obtained clustered into 7,863 unigenes composed of 2,845 contigs and 5,018 singletons. The total number of P. sojae unigenes matching sequences in the genome assembly was 7,412 (94%). Of these unigenes, 7,088 (90%) matched gene models predicted from the P. sojae sequence assembly, but only 2,047 (26%) matched P. ramorum gene models. Analysis of EST frequency from different growth conditions and morphological stages revealed genes that were specific to or highly represented in particular growth conditions and life stages. Additionally, our results indicate that, during infection, the pathogen derives most of its carbon and energy via glycolysis of sugars in the plant. Sequences identified with putative roles in pathogenesis included avirulence homologs possessing the RxLR motif, elicitins, and hydrolytic enzymes. This large collection of P. sojae ESTs will serve as a valuable public genomic resource.
从大豆疫霉P6497的四个发育阶段构建了六个独特的表达序列标签（EST）文库。从菌丝体、游动孢子、萌发的孢囊以及被大豆疫霉严重感染的大豆（Glycine max (L.) Merr.）品种哈罗索伊的组织中提取RNA。三个文库分别由在限定培养基、复合培养基和营养受限培养基上生长的菌丝体制备。获得的26,943条高质量序列聚类成7,863个单基因，其中包括2,845个重叠群和5,018个单拷贝序列。在基因组组装中与大豆疫霉单基因匹配的序列总数为7,412条（94%）。在这些单基因中，7,088条（90%）与从大豆疫霉序列组装预测的基因模型匹配，但只有2,047条（26%）与樟疫霉基因模型匹配。对来自不同生长条件和形态阶段的EST频率分析揭示了在特定生长条件和生命阶段特异或高度表达的基因。此外，我们的结果表明，在感染过程中，病原体通过植物中糖的糖酵解获取大部分碳和能量。鉴定出在致病过程中具有假定作用的序列包括具有RxLR基序的无毒同源物、激发子和水解酶。这个大量的大豆疫霉EST集合将成为宝贵的公共基因组资源。
