RESUMO
Two mutant potato virus X (PVX) movement protein (MP) genes (m 12K-Sal and m 12K-Kpn) were obtained by inserting specific linkers at the boundary between the N-terminal hydrophobic and putative transmembrane segment, and the central invariant hydrophilic region of the respective 12 kDa, 12K, triple gene block (TGB) protein. Several transgenic potato lines which expressed m 12K-Sal or m 12K-Kpn to different degrees were resistant to infection by PVX, potato aucuba mosaic potexvirus and the carlaviruses potato virus M and S over a wide range of inoculum concentrations (3-300 micrograms/ml). However, they were not resistant to potato virus Y, which lacks a TGB protein. We suggest that the resistance of m 12K-Sal and m 12K-Kpn transgenic potato lines is MP-derived and not RNA-mediated.
Assuntos
Vírus de Plantas/genética , Proteínas Virais/fisiologia , Sequência de Aminoácidos , Dados de Sequência Molecular , Proteínas do Movimento Viral em Plantas , Plantas Geneticamente Modificadas , RNA Viral/fisiologiaRESUMO
We cloned and sequenced a rat cDNA encoding the 2'-5' oligoadenylate synthetase, a component of the mammalian interferon-induced antiviral response, and used Agrobacterium-mediated transformation to generate transgenic potato clones expressing this mammalian enzyme. In transgenic plants infected with potato virus X and followed under field conditions, virus concentrations in leaves and in tubers were significantly lower than in nontransgenic controls. Additionally, virus concentration in the leaves of five transgenic clones and in tubers of one clone was also lower than in transgenic potatoes expressing potato virus X coat protein.
