title: Phylogenetic characteristics, genomic heterogeneity and symptomatic variation of five closely related Japanese strains of Potato virus X.
abstract: To elucidate the genomic determinants of Potato virus X (PVX) strains, which cause diverse responses in host plants, we determined the complete genomic RNA sequences of four Japanese PVX strains: PVX-BS, -BH, -OG, and -TO. These four strains, plus the previously sequenced PVX-OS strain, differ in their pathogenicity in wild potato (Solanum demissum) and tobacco (Nicotiana tabacum cv. Samsun NN). The genomic sequences of these five PVX strains were highly homologous (i.e., the nucleotide sequence identity ranged from 95.4 to 98.5%). Phylogenetic analysis indicated that the Japanese PVX strains originated from an ancestral PVX strain in the European group, and that the virulence of these strains in both S. demissum and tobacco is not correlated with their phylogenetic relationships, suggesting that the pathogenicity of each strain in these host plants is determined by a relatively small number of nucleotides and can easily be altered independent of phylogenetic relationships. Particularly, OS, BH, and BS, which respectively produce markedly contrasting ringspot, mosaic, and asymptomatic infections in tobacco leaves, were the most closely related, suggesting that these three strains are an attractive model for analyzing the genetic determinants causing these symptoms. A possible correlation between the genomic and biological differences of these strains is discussed.
authors.affiliation: Laboratory of Bioresource Technology, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Chiba, Kashiwa, 277-8562, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Komatsu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kagiwada
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Takahashi
authors.forename: Takuma
authors.initials: T
authors.lastname: Mori
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamaji
authors.forename: Hisae
authors.initials: H
authors.lastname: Hirata
authors.forename: Johji
authors.initials: J
authors.lastname: Ozeki
authors.forename: Akiko
authors.initials: A
authors.lastname: Yoshida
authors.forename: Masashi
authors.initials: M
authors.lastname: Suzuki
authors.forename: Masashi
authors.initials: M
authors.lastname: Ugaki
authors.forename: Shigetou
authors.initials: S
authors.lastname: Namba
mesh_terms: D000595:Amino Acid Sequence; D019143:Evolution, Molecular; D014644:Genetic Variation; D016679:Genome, Viral; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000821:virology*; D017863:Potexvirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D016415:Sequence Alignment; D011198:Solanum tuberosum / Q000821:virology*; D014026:Nicotiana / Q000821:virology; D014774:Virulence