Tobacco and potato samples showing symptoms of PVY were collected from different regions in Anhui Province,and the ELISA results of partial samples were positive.The total RNA was extracted from the positive samples b...Tobacco and potato samples showing symptoms of PVY were collected from different regions in Anhui Province,and the ELISA results of partial samples were positive.The total RNA was extracted from the positive samples by TRIZOL methods.Specific primer pair was designed to amplify cp gene of PVY by RT-PCR.Sequencing results indicated that the full length of cp gene of PVY from tobacco(PVY-CP-4) and potato(PVY-CP-7) is 801 nts,and each of them encodes 266 amino acids.A phylogenetic tree based on alignment of cp nucleotide sequences was constructed and the sequence comparing of cp gene was conducted.The results showed that PVY-CP-4 could be grouped into one branch with PVYO and PVYN:O and shared the highest sequence similarity(99.4%) with PVYO(EF026074).It was suggested that PVY-CP-4 derived from tobacco in Hefei might belong to PVYO.PVY-CP-7 clustered together with PVYN and PVYNTN and formed another branch.Furthermore,PVY-CP-7 shared the highest sequence similarity(98.3%) with PVYNTN(AJ890347),PVYNTN(EF026075) and PVYNTN(AJ585342).It was supposed that PVY-CP-7 derived from potato in Wuhe probably belonged to PVYNTN.展开更多
We have reported that cDNA derived from entire coat protein (CP) gene of potato virus Y (PVY) could induce resistance to PVY infection in transgenic tobacco plants, and the resistance was further demonstrated to be RN...We have reported that cDNA derived from entire coat protein (CP) gene of potato virus Y (PVY) could induce resistance to PVY infection in transgenic tobacco plants, and the resistance was further demonstrated to be RNA-mediated rather than coat protein-mediated. In this study, we cloned cDNA fragments of 202 bp, 417 bp, and 603 bp in length derived from the 3′ end of the PVY CP gene, and the cDNA fragments were introduced into tobacco (var. NC89) plants via Agrobacterium-mediated transformation system. The results of resistance assay showed that the CP cDNA fragments of 417 bp and 603 bp could confer resistance of the trans-genic plants to PVY infection, but the fragment of 202 bp in length could not. Molecular analysis revealed that the resistance was RNA-mediated, which is believed to be a result of post-transcriptional gene silencing. The results indicate that the length of cDNA fragments needed for resistance induction was located somewhere between 202 bp and 417 bp from the 3′ end of PVY CP gene.展开更多
文摘Tobacco and potato samples showing symptoms of PVY were collected from different regions in Anhui Province,and the ELISA results of partial samples were positive.The total RNA was extracted from the positive samples by TRIZOL methods.Specific primer pair was designed to amplify cp gene of PVY by RT-PCR.Sequencing results indicated that the full length of cp gene of PVY from tobacco(PVY-CP-4) and potato(PVY-CP-7) is 801 nts,and each of them encodes 266 amino acids.A phylogenetic tree based on alignment of cp nucleotide sequences was constructed and the sequence comparing of cp gene was conducted.The results showed that PVY-CP-4 could be grouped into one branch with PVYO and PVYN:O and shared the highest sequence similarity(99.4%) with PVYO(EF026074).It was suggested that PVY-CP-4 derived from tobacco in Hefei might belong to PVYO.PVY-CP-7 clustered together with PVYN and PVYNTN and formed another branch.Furthermore,PVY-CP-7 shared the highest sequence similarity(98.3%) with PVYNTN(AJ890347),PVYNTN(EF026075) and PVYNTN(AJ585342).It was supposed that PVY-CP-7 derived from potato in Wuhe probably belonged to PVYNTN.
基金This work was supported by the National Natural Science Foundation of China(Grant No.30270875)Shandong Province Natural Science Foundation(Grant No.Z2000D02)Shandong Province Science and Technology Development Project.
文摘We have reported that cDNA derived from entire coat protein (CP) gene of potato virus Y (PVY) could induce resistance to PVY infection in transgenic tobacco plants, and the resistance was further demonstrated to be RNA-mediated rather than coat protein-mediated. In this study, we cloned cDNA fragments of 202 bp, 417 bp, and 603 bp in length derived from the 3′ end of the PVY CP gene, and the cDNA fragments were introduced into tobacco (var. NC89) plants via Agrobacterium-mediated transformation system. The results of resistance assay showed that the CP cDNA fragments of 417 bp and 603 bp could confer resistance of the trans-genic plants to PVY infection, but the fragment of 202 bp in length could not. Molecular analysis revealed that the resistance was RNA-mediated, which is believed to be a result of post-transcriptional gene silencing. The results indicate that the length of cDNA fragments needed for resistance induction was located somewhere between 202 bp and 417 bp from the 3′ end of PVY CP gene.
