Jonghee Oh

Occurrence of Viruses Infecting Foxtail Millet ( Setaria italica ) in South Korea

한해살이풀로서(Ha와 Lee, 2001), 원산지는 중앙아시아와 동북아시아로 알려져 있다 (Li와 Wu, 1996). 동유럽, 중앙아시아, 동아시아 지역에서는 주요 곡물로서 재배되고 있으며, 아프리카, 아메리카, 호 주 등에서는 조류 등의 사료용으로 일부 재배되고 있다(De Wet 등, 1979). 국내에서 조는 1960년대까지 주요 작물로 널 리 재배되었으며(Kim 등, 2009), 주로 엿, 떡, 소주 등의 일부 재료로 이용되었다(Ha와 Lee, 2001). 이후, 조의 재배는 벼와 밀 등 주요 작물과 비교하여 수량과 수익성이 낮아 생산량 이 지속적으로 감소하였다. 통계청 보고에 따르면, 조의 생 산량은 2004년 2,644톤에서 2009년 1,360톤으로 급격히 감 소하였다(Kim, 2012; 통계청). 최근 건강에 대한 관심이 높아 지면서 조와 같은 잡곡은 웰빙식품, 기능성식품에 대한 소 비자의 선호도가 높아지며 관심이 증대하고 있지만(Lee 등, 2012), 수량과 직접적인 관련이 있는 병해충에 관한 체계적 인 연구들은 부족한 실정이다. 조의 경우 현재까지 2종의 바이러스(Rice black-streaked dwarf virus [RBSDV], Rice stripe virus [RSV])만이 보고되어 있어 바이러스 무병종자의 보급과 저항성 품종 개발 등의 연구에 제한적일 수밖에 없다. 따라 서 본 연구에서는 국내 조에서 발생하는 바이러스 조사를 수행하였으며, next generation sequencing (NGS)와 reverse

Molecular Verification of Bloom-forming Aphanizomenon flos-aquae and Their Secondary Metabolites in the Nakdong River

Aphanizomenon spp. have formed harmful cyanobacterial blooms in the Nakdong River during spring, autumn, and now in winter, and the expansion of blooming period and area, associated with the global warming is predicted. The genus Aphanizomenon has been described to produce harmful secondary metabolites such as off-flavors and cyanotoxins. Therefore, the production of harmful secondary metabolites from the Aphanizomenon blooms in the Nakdong River needs to be monitored to minimize the risk to both water quality and public health. Here, we sampled the cyanobacterial blooms in the Nakdong River and isolated ten Aphanizomenon strains, morphologically classified as Aphanizomenon flos-aquae Ralfs ex Bornet et Flahault 1888. Phylogenetic analysis using 16S rRNA and internal transcribed spacer (ITS) region nucleotide sequences confirmed this classification. We further verified the harmful secondary metabolites-producing potential of A. flos-aquae isolates and water samples containing cyanobacterial blooms using PCR with specific primer sets for genes involved in biosynthesis of off-flavor metabolites (geosmin) and toxins (microcystins, saxitoxins and cylindrospermopsins). It was confirmed that these metabolite biosynthesis genes were not identified in all isolates and water samples containing only Aphanizomenon spp. Thus, it is likely that there is a low potential for the production of off-flavor metabolites and cyanotoxins in Aphanizomenon blooms in the Nakdong River.

Incidence of Viral Diseases and Occurrence of Three Unreported Viruses in Yams in Korea

United Nations (FAO), yams (Dioscorea species, Dioscoreaceae) are the most important food tuber crop, a class of foods including potatoes, sweet potatoes, and cassava (FAO, 2012). Approximately 600 species of yams are distributed throughout the world, and only 10 of these species are used as edible crops (Mambole et al., 2014). Yams are an important traditional crop and staple food and provide income to small farmers in West Africa (Asiedu and Sartie, 2010). Moreover, yams are commonly used as medicines and vegetables (Kwon et al., 2016a), and more than 4,000 tons are produced in Korea each year. Yams are propagated through seeds or tubers, resulting in accumulation of various pathogens, such as viruses, fungi, and bacteria. Of the many pathogens that affect these plants, viral infections in particular, can cause significant reductions in the yield and quality of yam crops (Mantell and Haque, 1978). Approximately eight viruses (Chinese yam necrotic mosaic virus [ChYNMV], Dioscorea alata badnavirus [DaBV], D. alata virus [DAV], Dioscorea dumetorum virus [DDV], Dioscorea esculenta virus [DEV], Yam mosaic virus [YMV], Yam mild mosaic virus [YMMV], and Japanese yam mosaic virus [JYMV]) have been reported in Asia (Kenyon et al., 2001; Wang et al., 2015), whereas only two viruses (Broad bean wilt virus 2 [BBWV2] and ChYNMV)

A Survey of Viral Diseases of Proso Millet ( Panicum miliaceum L.) and Sorghum ( Sorghum bicolor L.) in South Korea

Throughout year 2015 to 2016, 101 proso millet and 200 sorghum samples were collected from five provinces in South Korea. The samples were subjected to paired-end RNA sequencing and further analyzed by RT-PCR. The results indicated that Rice black-streaked dwarf virus (RBSDV) was detected from sorghum collected in Gyeongsang province. The other four viruses, including RBSDV, Rice stripe virus (RSV), Barley virus G (BVG), and Cereal yellow dwarf virus (CYDV), were detected from proso millet. Among four viruses, both RSV and RBSDV were identified high frequency from proso millet collected from Gyeongsang province. Otherwise, BVG was nearly equally identified from five provinces, suggesting that the virus was supposedly widespread nationwide. RBSDV was first identified from both proso millet and sorghum in South Korea. The other virus annotated CYDV identified proso millet was shown to have relatively low identities compared to CYDV previously reported, suggesting that the virus might be new member of Polerovirus.

First Complete Genome Sequence of Barley Virus G Identified from Proso Millet (Panicum miliaceum) in South Korea

ABSTRACT The complete genome sequence of an Uiseong isolate of barley virus G (BVG) on proso millet plants in a field in South Korea was determined by RNA sequencing and Sanger sequencing. To our knowledge, this is the first complete genome sequence report of BVG infecting proso millet in South Korea.

Reverse Transcription Loop-Mediated Isothermal Amplification Assay for Rapid Detection of Soybean yellow mottle mosaic virus

콩(Glycine max)은 식물성 단백질 공급원으로 경제적으로 중요한 작물 중 하나이다. 전 세계적으로 46종의 바이러스 가 콩에 감염되는 것으로 보고되었으며(Tolin과 Lacy, 2004), 국내에서는 Soybean mosaic virus (SMV)를 포함하여 현재까지 11종이 보고되어 있다(Lee 등, 2013, 2015; Lim 등, 2014; Shin 등, 2014). 이 중에서, Kim (2006)에 의해서 최초 보고된 콩황 화모틀모자이크바이러스(Soybean yellow mottle mosaic virus, SYMMV)는 Carmovirus속, Tombusviridae과에 속하는 바이러 스이다. SYMMV의 게놈은 양성-극성 외가닥 RNA (positive sense single stranded RNA) 바이러스로 여섯 개의 열린 해독 틀(open reading frame)과 비번역영역(untranslated region)으 로 구성되어 있다(Nam 등, 2009). SYMMV는 콩, 돌콩(Glycine soja), 새팥(Vigna angularis var. nipponensis), 토끼풀(Trifolium repens), 비수리(Lespedeza cuneate) 등 콩과 식물에 국한된 자 연기주 범위를 가지며, 돌콩에서 종자전염을 통한 안정된 생활사를 취하는 것으로 알려져 있다(Lee와 Kim, 2013). 최근 콩 재배지의 바이러스병 발생조사결과에 따르면 SYMMV는 SMV, Soybean yellow common mosaic virus (SYCMV)와 함께 국 내 콩에서 빈번하게 발생하는 주요 바이러스병이며(Cho 등, 2013; Lee 등, 2013), 2013년 국내 전국 콩 단위조사 결과 발병 률이 가장 높은 바이러스로 확인되었다(Seo 등, 2014).

Survey of the Incidence of Viral Infections in Calanthe spp. and Characterization of a GW Isolate of Cymbidium mosaic virus in Korea

Cymbidium mosaic virus (CymMV) is a major virus infecting orchid plants and causing economic loss. In this study, the incidence of viral infection in Calanthe spp. at the Korean Institute of Calanthe was investigated using reverse transcription polymerase chain reaction. The CymMV infection rate was 42%, and the two viruses Odontoglossum ringspot virus and Cucumber mosaic virus had frequencies of 8% and 2%, respectively. Additionally, we characterized an isolate of CymMV, CymMV-GW, using biological tests and examined the nucleotide sequence properties of its complete genome. CymMVGW induced chlorotic ringspots and chlorotic spot symptoms in inoculated leaves of Chenopodium amaranticolor and Nicotiana benthamiana, respectively. In this study, we have for the first complete genome sequence of CymMV-GW in Korea. The CymMV-GW genome was 6,225 nucleotides in length, excluding the poly-(A) tail, and showed whole-genome nucleotide and amino acid sequence identities of 97.7% and 100%, respectively, with the NJ-1 isolate of CymMV. Here, we report the complete genome sequence of the CymMV-GW isolate and viral infection rates for Calanthe spp. in Korea.