Grapevine virus T (GVT) is a new member of the genus Foveavirus and has been reported to infect grapevines in several European countries. In 2018, GVT was detected for the first time in California in a domestic selection of wine grape, cv. Lambrusca di Alessandria, via high-throughput sequencing (HTS). To further investigate the presence of GVT in other grapevine plants, a two-step reverse transcription (RT)-PCR assay involving degenerate primers was developed. In order to cover the high genetic diversity of GVT, the sequences of available isolates were aligned to identify a conserved region in the coat protein gene that was a suitable target for the assay. The results of the RT-PCR assay showed that GVT was present in three additional grapevine selections among 416 plants integrating the Foundation Plant Services introduction pipeline; all were later confirmed by HTS. A complete and three near-complete genomes of the four GVT isolates were characterized and found to be divergent, sharing an overall 81% pairwise identity in their nucleotide sequences. This suggested that the new RT-PCR assay was effective in detecting a broad range of GVT variants. The RT-PCR detection method developed in this study would be useful for routine virus testing.

中文翻译：

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RT-PCR简并引物的开发克服了葡萄病毒T的高遗传多样性。

葡萄病毒T（GVT）是凹叶病毒的新成员，据报道在多个欧洲国家感染了葡萄。在2018年，GVT在加利福尼亚首次在国内精选的酿酒葡萄中被检测到。Lambrusca di Alessandria，通过高通量测序（HTS）。为了进一步研究其他葡萄植物中GVT的存在，开发了涉及简并引物的两步逆转录（RT）-PCR分析方法。为了覆盖GVT的高度遗传多样性，将可用分离株的序列进行比对，以鉴定外壳蛋白基因中的保守区域，该区域是该测定的合适靶标。RT-PCR分析的结果表明，在416种植物中，在整合了Foundation Plant Services引入管道的另外3种葡萄中，存在GVT。所有这些后来都被HTS确认。四个GVT分离物的完整和三个接近完整的基因组经过鉴定，发现存在差异，在其核苷酸序列中共有81％的成对同一性。这表明，新的RT-PCR测定法可有效检测多种GVT变异体。在这项研究中开发的RT-PCR检测方法将对常规病毒检测有用。