Cucumber mosaic virus Paf 계통의 약독 병징과 관련된 satellite RNA의 유전자 해석 |
성미영, 정민영, 이상용1, 류기현2, 최장경* |
강원대학교 생물환경학부, 1강원대학교 산림자원학부, 2서울여자대학교 환경생명과학부 |
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Genomic Analysis of Satellite RNA of Cucumber mosaic virus-Paf Related with Mild Symptoms |
Mi-Young Sung, Min-Young Jung, Sang-Yong Lee1, Ki-Hyun Ryu2, Jang-Kyung Choi* |
Division of Biological Environment, Kangwon National University, Chunchon 200-701, Korea 1Division of Forest Resources, Kangwon National University, Chunchon 200-701, Korea 2Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, Korea |
Correspondence:
Jang-Kyung Choi,Phone)+82-33-250-6432, Fax)+82-33-241-1721, E-mail)jkchoi@kangwon.ac.kr |
Received: November 25, 2004 |
Abstract |
Recently, we reported a satellite RNA (Paf-satRNA) which is encapsidated in a pepper isolate of Cucumber mosaic virus (CMV-Paf) regulated symptom attenuation of the helper virus. To characterize mild symptom domain of Paf-satRNA, a series of chimeric cDNAs of satRNAs were created by using full-length cDNA clones of Paf-satRNA and a Pep-satRNA, chlorosis-inducing satRNA in pepper plants, and analyzed for determinants of symptom attenuation. When compared the nucleotide sequences, the 3' and 5' terminal sequences of the two wild-type (wt) satRNAs contained relatively conserved sequences which are the typical to CMV satRNA. Ten bases insertions were found in PepY-satRNA, and two variable regions, 81st to 113th and 183rd to 265th from the 5'-end, were located in the middle parts of the satRNAs. To delineate the attenuated symptom-related domain for the Paf-satRNA, in vitro transcripts RNAs transcribed from the wt cDNAs and constructed chimeric cDNAs were combined with genomic RNAs, RNA1, RNA2 and RNA3, of CMV-Fny and inoculated onto Nicotiana benthamiana plants. These transcripts were fully infectious onto the N. benthamiana and infectivity was confirmed by the RT-PCR. Chimeric Paf(H/N)-satRNA and PepY(N/A)-satRNA as well as Paf-satRNA induced very mild mosaic or symptomless infection on N. benthamiana. By contrast, typical mosaic symptom and stunting of infected plants were induced when PepY-satRNA, PepY(H/N)-satRNA and Paf(N/A)-satRNA were infected to N. benthamiana. Paf-satRNA coinfected with CMV-Fny RNAs induced very mild to sympomless on pepper plants whereas PepY-satRNA-infected pepper expressed typical chlorosis mosaic symptom. Two kinds of chimeric mutants, Paf(H/N)-satRNA and PepY(N/A)-satRNA, induced mild mosaic or symptomless infection onto pepper plants, while PepY(H/N)-satRNA and Paf(N/A)-satRNA showed typical chlorosis and mosaic symptom with stunting. This results suggest that mild symptom-related domain for the Paf-satRNA was located on HpaI-NarI region. |
Key Words:
Cucumber mosaic virus, Mild symptom domain, Satellite RNA |
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