RESUMO
The locus RTM1 is necessary for restriction of long-distance movement of tobacco etch virus in Arabidopsis thaliana without causing a hypersensitive response or inducing systemic acquired resistance. The RTM1 gene was isolated by map-based cloning. The deduced gene product is similar to the alpha-chain of the Artocarpus integrifolia lectin, jacalin, and to several proteins that contain multiple repeats of a jacalin-like sequence. These proteins comprise a family with members containing modular organizations of one or more jacalin repeat units and are implicated in defense against viruses, fungi, and insects.
Assuntos
Proteínas de Arabidopsis , Arabidopsis/genética , Lectinas/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , Antivirais/química , Mapeamento Cromossômico , Clonagem Molecular , Genes de Plantas , Lectinas/química , Dados de Sequência Molecular , Lectinas de Plantas , Proteínas de Plantas/química , Vírus de Plantas/patogenicidade , Alinhamento de SequênciaRESUMO
The genetic basis for susceptibility or nonsusceptibility of plants to viruses is understood poorly. Two selectable tobacco etch virus (TEV) strains were developed for identification of Arabidopsis thaliana mutants with either gain-of-susceptibility or loss-of-susceptibility phenotypes. These strains conferred a conditional-survival phenotype to Arabidopsis based on systemic expression of herbicide resistance or proherbicide sensitivity genes, thereby facilitating mass selections and screens for Arabidopsis mutants that enhance or suppress TEV replication, cell-to-cell movement, or long-distance movement. A multicomponent mechanism that restricts systemic invasion of TEV was identified through isolation of gain-of-susceptibility mutants with alterations at two loci.