First Report of Hop stunt viroid in Japanese Apricot (Prunus mume) in Korea

Abstract

HomePlant DiseaseVol. 101, No. 7First Report of Hop stunt viroid in Japanese Apricot (Prunus mume) in Korea PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Hop stunt viroid in Japanese Apricot (Prunus mume) in KoreaY. Jo, S. Lian, J. K. Cho, H. Chu, and W. K. ChoY. JoSearch for more papers by this author, S. LianSearch for more papers by this author, J. K. ChoSearch for more papers by this author, H. ChuSearch for more papers by this author, and W. K. ChoSearch for more papers by this authorAffiliationsAuthors and Affiliations Y. Jo , Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea S. Lian , College of Crop Protection and Agronomy, Qingdao Agricultural University, Qingdao, Shandong 266109, China J. K. Cho , The Taejin Genome Institute, Gadam-gil 61, Hoengseong, 25239, Republic of Korea H. Chu , Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea W. K. Cho , Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea; and The Taejin Genome Institute, Gadam-gil 61, Hoengseong, 25239, Republic of Korea. Published Online:9 May 2017https://doi.org/10.1094/PDIS-01-17-0059-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Viroids are the smallest pathogens, and they consist of a circular single-stranded RNA genome that does not encode any protein (Hammann et al. 2012). To date, 46 viroid species have been identified. One of them, Hop stunt viroid (HSVd) in the genus Hostuviroid has been identified in at least 17 plant species, such as citrus, grapevine, apricot, plum, and peach species, from 38 countries (Jo et al. 2017). The Prunus mume (mei), known as Japanese apricot, belongs to the genus Prunus in the family Rosaceae, and is mostly grown in China, Japan, and Korea. It is used for juices, alcohol flavoring, pickles, and traditional medicine. In a survey of viruses and viroids in Japanese apricot trees during September 2015, leaf samples from two plants representing two cultivars, Takada and Wallyoung, were collected from an orchard in Korea. The leaves of the two plants did not display any visible disease symptoms. The leaf samples were subjected to total RNA extraction using Fruit-mate for RNA Purification (Takara, Shiga, Japan) and the RNeasy Plant Mini Kit (Qiagen, Hilden, Germany) following the manufacturers’ instructions. Two libraries from the two cultivars were generated and paired-end (2 × 100 bp) sequenced by Illumina’s HiSeq 2000 system (Macrogen, Seoul, Korea), as described previously (Jo et al. 2016). We obtained 37,546,342 and 37,171,434 reads for Takada and Wallyoung, respectively. Raw sequence reads were assembled by the Trinity program (Haas et al. 2013), and the assembled contigs were subjected to a MEGABLAST search against a viral reference database. We identified two and four contigs associated with HSVd from Takada and Wallyoung, respectively. Reverse transcription (RT)-PCR was performed to confirm the presence of HSVd using HSVd-specific primers (5′-GCCCCGGGGCTCCTTTCTCAGGTAAG-3′ [position 85-60] and 5′-CCCGGGGCAACTCTTCTCAGAATCC-3′ [position 78-102]) based on the HSVd reference sequence (GenBank NC_001351.1) (Astruc et al. 1996). The amplified PCR products were cloned in pGEM-T-Easy Vector (Promega, Madison, WI) and sequenced. Based on the sequencing results from using the PCR amplicon, HSVd isolate Takada (KY445746) was 99% identical to the clone chi100Y-02-4-5 from grapevine from China (AB219944.1), while HSVd isolate Wallyoung (KY445747) was 98% identical to the clone 2hsvdh2-4 from hop from China (EU365352.1). To our knowledge, this is the first report of HSVd associated with Japanese apricot.