title: Differential screening reveals genes differentially expressed in low- and high-virulence near-isogenic Phytophthora sojae lines.
abstract: To explore the molecular mechanisms involved in virulence variations in Phytophthora sojae, the low-virulence isolate PS2 was inoculated successively on a resistant soybean (Glycine max) cultivar. After 14 successive inoculations, a high-virulence progeny, termed PS2-vir, was obtained and demonstrated to exhibit lower oospore production. DNA fingerprinting revealed no large-scale DNA differences in PS2 and PS2-vir. A suppression subtractive hybridization (SSH) approach was developed to investigate differences in gene expression between PS2 and PS2-vir in the early stages of soybean infection. Of the 323 sequences chosen for examination, 74 putative unigenes were identified that exhibit high expression in PS2-vir. These sequences are predicted to encode proteins involved in energy production, protein biosynthesis, cell signaling, cell-wall biogenesis, and transcription regulation. Ten clones were selected for temporal expression analysis using RT-PCR based on the results of the dot-blot screens. The possible genetic mechanisms involved in these phenomena are discussed.
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China.
authors.forename: Ziying
authors.initials: Z
authors.lastname: Wang
authors.forename: Yuanchao
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiaoren
authors.initials: X
authors.lastname: Chen
authors.forename: Gui
authors.initials: G
authors.lastname: Shen
authors.forename: Zhengguang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zheng
mesh_terms: D001483:Base Sequence; D002681:China; D016172:DNA Fingerprinting; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D005800:Genes, Fungal / Q000235:genetics*; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization / Q000379:methods; D010838:Phytophthora / Q000166:cytology / Q000235:genetics* / Q000472:pathogenicity*; D019105:Random Amplified Polymorphic DNA Technique; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013025:Glycine max / Q000382:microbiology*; D014774:Virulence
chemical_list: D018076:DNA, Complementary