Font Size: a A A

Pathogenicity And Stability Of βC1 Truncated DNAβ Molecules Associated With Geminiviruses And Application Of Truncated DNAβ Molecules

Posted on:2006-11-10Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y J QianFull Text:PDF
GTID:1103360152994087Subject:Plant pathology
Abstract/Summary:PDF Full Text Request
Geminiviruses are a group of plant viruses occurred worldwide and characterized by their unique twinned particles, which encapsidate a circular single-stranded DNA genome. In recent years, they cause destructive diseases in many important crops and have caused significant yield losses for crop production. A novel satellite DNA, referred to as DNAβ is found to be associated with monopartite begomoviruses and is found to be required for inducing typical symptoms in natural hosts. All reported DNAβ possesses a βC1 gene on the complementary strand, which has a conserved position and size. In order to further investigate the role of DNAβ in pathogenicity, the pathogenicity and stability of βCl truncated DNAβ molecules was investigated, furthermore, the βC1 truncated DNAβ was used for expression of foreign genes and inducing gene silencing.The function of βC1 gene of DNAβ associated with Tomato yellow leaf curl China virus isolate Y10 (TYLCCNV-Y10) was studied. A βC1 truncated Y10 DNAβ was constructed. Co-agroinoculation with TYLCCNV-Y10 showed the truncated DNAβ was infectious in Nicotiana benthamiana and N. glutinosa plants producing asymptomatic symptoms but not in N. tabacum Samsun, N. tabacum and Lycopersicon esculentum plants. The wild type Y10 DNAp co-agroinoculated with TYLCCNV-Y10 caused systemic infection in all the above hosts and induced severe disease symptoms. These results suggest that βC1 gene is a pathogenicity determinant and contributes to the infectivity of the disease complex of TYLCCNV and the satellite DNAβ. Results of Southern blot analysis indicate that βC1 gene is not required for TYLCCNV and DNAβ replication. However, the presence of βCl gene in DNAβ can increase both TYLCCNV and DNAβ accumulation in infected plants. The immunotrapping-PCR demonstrated the truncated Y10 DNAβ (1.0kb) was encapsidated by Y10 coat protein. The PCR and Southern blot analysis showed that the truncated Y10 DNAP was stable in N. benthamiana and N. glutinosa plants and could replicate when co-agroinoculation with other geminiviruses.The function of βC1 gene of DNAβ associated with Tobacco curly shoot virus isolate Y35 (TbCSV-Y35) was studied. A βCl truncated Y35 DNAβ was constructed. The truncated Y35 DNAβ was infectious in N. benthamiana, N. glutinosa, Petunia bybrida, N. tabacum Samsun, N. tabacum and Lycopersicon esculentum plants when co-infected with...
Keywords/Search Tags:Geminivirus, Tomato yellow leaf curl China virus, Tobacco curly shoot virus, DNAβ, βC1 truncated DNAβ, pathogenicity, stability, expression vector, virus induced gene silencing
PDF Full Text Request
Related items