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Course of viral origin and evolution indicates that the variability of the virus, and the evolution of the virus tend to generate more pathogenic strains, and therefore understand the laws of the evolution of the virus mutates, and contribute to the development of more targeted antiviral strategies, large area to avoid virus disease outbreak. Most plant virus RNA virus RNA recombination is one of the main ways the evolution of RNA viruses. RNA recombination phenomenon was confirmed in an increasing number of RNA viruses, but restructuring mechanism is not fully understood. Cucumber mosaic virus (Cucumber mosaic virus CMV) and tomato infertility virus (Tomato aspermy virus, TAV) ---, both belong to the same RNA genome viruses for the study, obtained by in vitro transcription of CMV RNA1 of CMV RNA2 of and TAV RNA3, combined into a false recombinant viruses were inoculated grams benthamiana (N.Clevelandii), occurrence of the situation and the pathogenicity of the recombinant viruses by detecting recombinant plant viral RNA recombination mechanism discussed specific results are as follows: (1 ) to the viral genomic RNA of the cDNA with a T7 promoter cloning vector CMV RNA1 CMV the RNA2 of T2b , CMV RNA2 of CMV the RNA2 of W2B and TAV RNA3 of △ 163 (A) get viral RNA as a template, in vitro transcription RNA1, RNA2 and RNA3 of different sources of artificial combinations of three kinds of fake recombinant virus c2 (A) <(C1C2 T3 △ 163 / sub>), qt (C1C2 T2B T3 △ 163 (A) ) and qw (C1C2 W2B T3 △ 163 (A) ). (2) artificially constructed fake recombinant c2, qt, qw were inoculated with Klinefelter smoke, c2 (with the Q-CMV2b) not infection activity, qt (with the V-TAV2b) and qw (with infection activity the WA Ⅱ-CMV2b) in Klinefelter smoke have the qt infection symptoms than the qw is more serious, and qt and qw infection symptoms are more important than Q-CMV, this will affect that different sources 2b protein false The recombinant virus symptoms. (3) The infected 14dpi, 28dpi and 35dpi systems incidence of total leaf RNA extraction were false recombinant CMV and TAV-specific probes for Northern blot analysis, the results showed that vaccination 35dpi position qt CMV RNA3 emergence of a new CMV-specific bands, but the position in CMV RNA3 with top, RT-PCR and sequence alignment analysis showed that, the artificial recombinant qt TAV RNA3 between CMV RNA1 restructuring, showed that TAV2b can promote the occurrence of RNA recombination. This process involves a variety of unstable recombination intermediates, diversified and recombination sites. (4) sequence analysis showed that the recombination sites are always distributed in TAV RNA3 2109nt-2386nt 277 nt interval and the restructuring of the two RNA sequences near the recombination sites homologous sequences 5'-AGGTC CGAAGACGTTAAACTAC -3 '(box1), but the recombination sites is not in the homologous sequences, but located downstream of non-homologous regions, apparently box1 and did not play the role to promote homologous recombination. Wherein the sequence of the longest recombinant TAV RNA3 end of the lap of the conserved region of the CMV RNA1 310nt. This restructuring, more particularly, a new restructuring mechanism. Q-CMV RNA all recombination intermediates the 3 'end with the highly conserved TLS sequence, may be provided in the viral replication process, since replication of CMV replication enzyme, while it for the CMV 310nt start identification more effective this highly conserved region can assist replication enzymes find encoding reading frames downstream of the overlapping sites, thus providing better the synthesis of RNA. (5) Construction of recombination intermediates virus cloning vectors, in vitro transcription, to obtain intermediate sham recombinant virus. Respectively infection Klinefelter smoke, symptoms probably the same, are mottled next pulse, dark green, similar to the symptoms of CMV infection. By RT-PCR analysis, filter out the stable presence of the recombinant virus C1C2 T2b T3 PrE-8 . The RNA3 sequence with the longest sequence of intermediates. Presumably TAV3 pRE-8 of the 3 'end of the highly conserved regions, increasing the virus C1C2 T2b T3 PRE-8 infection activity, relative to other recombination intermediates have a competitive advantage, and therefore stability to survive. Infection Klinefelter cigarette adapter for four generations, purified virus, infecting different kinds of tobacco, and diagnostic analysis. Found the C1C2 T2B T3 pRE-8 resulting in the heart leaf tobacco (N. glutinosa) top necrosis, suggesting 2b protein host interaction prompted necrosis. Other tobacco mosaic or mottled show varying degrees.
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