Inoue-Nagata Alice Kazuko, Franco Carolina de Mello, Martin Darren Patrick, Rezende Jorge Alberto Marques, Ferreira Gleydson Barros, Dutra Luisa Silva, Nagata Tatsuya
Embrapa Vegetables, Brasilia, DF, Brazil.
Virus Genes. 2007 Aug;35(1):119-27. doi: 10.1007/s11262-006-0032-5. Epub 2006 Oct 6.
Papaya ringspot virus-type W (PRSV-W) is one of the most economically threatening viruses of cucurbits in Brazil. Premunization is one of the most effective PRSV control measures currently applied in squash and zucchini crops. PRSV-W-1, a mild and premunizing strain of PRSV has been successfully used to protect cucurbits against both the severe PRSV-W-C strain and other Brazilian PRSVs. To aid in understanding the mechanism by which PRSV-W-1 premunization operates, the complete genome sequences of PRSV-W-1 and PRSV-W-C were determined. PRSV-W-1 had a genome size of 10,332 nucleotides, whereas indels within the coat protein encoding gene meant that the genome size of PRSV-W-C was six nucleotides shorter than that of the mild strain. The genomes of the two strains shared 94.63% nucleotide sequence identity, with the 5' UTR and P1 being the most variable regions, and the coat protein and 3' UTR being the most conserved. Rigorous recombination analysis revealed that neither PRSV-W-1 nor PRSV-W-C was obviously recombinant, there was significant evidence that many other fully sequenced PRSV genomes were recombinant.
番木瓜环斑病毒W型（PRSV-W）是巴西葫芦科作物中最具经济威胁的病毒之一。预先免疫是目前南瓜和西葫芦作物中应用最有效的PRSV防控措施之一。PRSV-W-1是一种温和的、具有预先免疫作用的PRSV毒株，已成功用于保护葫芦科作物免受严重的PRSV-W-C毒株和其他巴西PRSV毒株的侵害。为了有助于理解PRSV-W-1预先免疫的作用机制，测定了PRSV-W-1和PRSV-W-C的完整基因组序列。PRSV-W-1的基因组大小为10332个核苷酸，而外壳蛋白编码基因内的插入缺失意味着PRSV-W-C的基因组大小比温和毒株短6个核苷酸。这两个毒株的基因组具有94.63%的核苷酸序列同一性，5'UTR和P1是最可变的区域，外壳蛋白和3'UTR是最保守的。严格的重组分析表明，PRSV-W-1和PRSV-W-C都不是明显的重组体，但有大量证据表明许多其他已完成全序列测定的PRSV基因组是重组体。
