Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Identification of Pns6, a putative movement protein of RRSV, as a silencing suppressor | Wu et al. Virology Journal 2010 7 335 http content 7 1 335 VIROLOGY JOURNAL SHORT REPORT Open Access Identification of Pns6 a putative movement protein of RRSV as a silencing suppressor f 1 f 2 1 1 tA 1 Jianguo Wu Zhenguo Du Chunzheng Wang Lijun Cai Meiqun Hu Qiying Lin Zujian Wu Yi Li2 Lianhui Xie1 Abstract RNA silencing is a potent antiviral response in plants. As a counterdefense most plant and some animal viruses encode RNA silencing suppressors. In this study we showed that Pns6 a putative movement protein of Rice ragged stunt virus RRSV exhibited silencing suppressor activity in coinfiltration assays with the reporter green fluorescent protein GFP in transgenic Nicotiana benthamiana line 16c. Pns6 of RRSV suppressed local silencing induced by sense RNA but had no effect on that induced by dsRNA. Deletion of a region involved in RNA binding abolished the silencing suppressor activity of Pns6. Further expression of Pns6 enhanced Potato virus X pathogenicity in N. benthamiana. Collectively these results suggested that RRSV Pns6 functions as a virus suppressor of RNA silencing that targets an upstream step of the dsRNA formation in the RNA silencing pathway. This is the first silencing suppressor to be identified from the genus Oryzavirus. Plant infecting reoviruses are grouped into three genera namely Phytoreovirus Fijivirus and Oryzavirus 1 . RRSV belongs to the genus Oryzavirus. It infects plants in the family Graminae and is transmitted in a persistent manner by brown plant hoppers. The disease caused by this virus was first discovered in 1976-1977 in Indonesia and Philippines. Then the disease became prevalent in most rice-growing countries in south-eastern and far-eastern Asia causing great yield losses to rice production 2 . RRSV virion has an icosahedral particle which consists of a polyhedral core surrounded by flat spikes about 20 nm wide and 10 nm high 3 . The RRSV genome comprises 10 double stranded RNAs with molecular weights .
