• The Plant Pathology Journal
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• v.18 no.6
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• pp.313-316
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• 2002

Systemic virus symptoms caused by a Potexvirus were observed on leaves of infected hosta (Hasta spp.) plants cultivated in Seoul, Korea. Symptoms on diseased hosta plants include mosaic, mottle, irregular blotchy patches, and chlorotic spots on or distortion of the leaves. No other viruses, such as Cucumber mosaic virus, Lily symptomless virus, or Potyvirus, were detected from the same plants by electron microscopy and by Western blot and RT-PCR analyses, indicating that they were singly infected by the potexvirus. The symptoms differed among cultivars and species of hosta, and affected the quality of plants for commercialization, as well as, plant growth and flowering of susceptible cultivars. Most of the cultivars and species investigated were susceptible to the virus, while some were not infected by the virus at all. Purified virus particles were of filamentous type with unaggregated forms 540 nm in length, which is a typical potexviral morphology. The virus consisted of a single-stranded RNA molecule of 6 kb long for genome and single component of coat protein (CP) about 27 kDa. The CP strongly reacted with the antiserum against Hosta vims X (HVX), suggesting that the virus is an isolate of HVX. This is the first report of the occurrence and identification of HVX from hosta plants in Korea.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.144.2-145
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• 2003

This study was performed to investigate the incidence of Hosta uirus X (HVX), a Potexvirus, from cultivated hosta ornamental plants in Korea and to ascertain seed transmission of the virus from infected parent plant to progeny ones for breeding program of hosta plants. Infection rate of HVX in cultivated hostas was 25.6 ％ (11 out of 43 collected samples contained HVX) based on Western blot and RT-PCR detection methods. Most of HVX-infected hostas showed visible systemic leaf symptoms (mosaic, mottle, curling, stunting or combinations). Variability of HVX was confirmed by sequences of coat protein gene of individual isolates from different hostas. HVX was seed-transmitted on Hosta 'Blue Cadet'. The virus was detected from seeds, and sprouts and seedlings from the virus-contaminated seed sources. Over 7.5 ％ of seeds were HVX-contaminated surveyed in this study, Our data suggest that HVX can be transmitted by seed source, and indexing of the virus should be done for breeding program of Hosta.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.123.1-123
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• 2002

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.113.1-113
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• 2003

A potexvirus, Hosta virus X (HVX-Kr), causing mosaic and mottle symptoms was isolated from hosta plants (Hosta spp.), and its entire genome RNA sequence was determined. in Korea using cDNA library and RACE methods. The genome of HVX encodes five open reading frames coding for viral replicase, triple gene block (TGB), and viral coat protein (CP) from the 5'to 3' ends, which is a typical genome structure of potexviruses. The 3-terminal region of the virus includes the TGBI (26 kDa), TGB2 (13 kDa), TGB3 (8 kDa), and 23 kDa coat protein (CP) and the 3-nontranslated region (NTR). The CP gene of the type isolate of HVX (HVX-U) was amplified by RT-PCR and its nucleotide sequence was determined. The CPs of HVX-Kr and HVX-U had 100％ and 98.9％ identical amino acids and nucleotides, respectively. Most of the regions of the genome HVX had over 50％ nucleotide identical to other sequenced potexviruses. This is the first report of complete genome sequence information of HVX and molecular evidence supporting the virus as a distinct species of the genus Potexvirus.