Assuntos
Begomovirus/genética , Solanum lycopersicum/virologia , Doenças das Plantas/virologia , Plantas Geneticamente Modificadas/virologia , Interferência de RNA , Vírus Satélites/genética , Begomovirus/fisiologia , Solanum lycopersicum/genética , Solanum lycopersicum/imunologia , Omã , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Doenças das Plantas/prevenção & controle , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Vírus Satélites/fisiologiaRESUMO
Tobamovirus movement proteins play a determinant role in the establishment of infections in plants, allowing the local movement of viral RNA genome through plasmodesmatas. We expressed the movement protein (MP) of the crucifer- and garlic-infecting Tobacco Mosaic Virus strain Cg (TMV-Cg) in both resistant Xanthi NN and sensitive Xanthi nn Nicotiana tabacum plants. MP-Cg function was assayed by inoculating transgenic plants with a trafficking-deficient mutant of TMV strain U1. Following infection, local necrotic lesions were developed in resistant transgenic plants, and a systemic infection was produced in sensitive tobaccos. Thus, movement function of the mutant virus was complemented in trans by MP-Cg expressed in transgenic plants, causing the same symptoms as wild-type strain. We demonstrated that the function of MP-U1 could be replaced efficiently by MP-Cg, even though these proteins share only 36% of identity. Similar hydrophobic patterns of MP-Cg and MP-U1 suggests structure and function conservations of both proteins. This work is an example of how two tobamoviruses differing in their host range help to understand viral movement mechanism during the infection.
Assuntos
Mutação/genética , Doenças das Plantas/virologia , Proteínas do Movimento Viral em Plantas/genética , Plantas Geneticamente Modificadas/virologia , Vírus do Mosaico do Tabaco/genética , Nicotiana/virologia , Expressão Gênica , Genótipo , Fatores de Tempo , Nicotiana/genéticaRESUMO
A system for the genetic transformation of maize was developed for two Costa Rican varieties: CR-7 and Diamantes 8843, that can allow the subsequent transfer of viral-derived genes in order to confer resistance to the disease caused by maize rayado fino virus (MRFV). The method is based on particle bombardment of organogenic calli derived from shoot tips. On the other hand, the molecular construction pRFcp-bar, containing the coat protein gene of MRFV and the marker gene bar, was elaborated. For the visual selection of the transformed material was used also the plasmid pDM803 that contains the reporter gene uidA (GUS). The results indicate that devices evaluated: the PIG ("Particle Inflow Gun") and the Bio-Rad are both enough efficient to transfer foreign genes to the genome of the maize.