Mutations in the tobacco mosaic virus 30-kD protein gene overcome Tm-2 resistance in tomato.
AUTOR(ES)
Meshi, T
RESUMO
A resistance-breaking strain of tobacco mosaic virus (TMV), Ltb1, is able to multiply in tomatoes with the Tm-2 gene, unlike its parent strain, L. Nucleotide sequence analysis of Ltb1 RNA revealed two amino acid changes in the 30-kD protein: from Cys68 to Phe and from Glu133 to Lys (from L to Ltb1). Strains with these two changes generated in vitro multiplied in tomatoes with the Tm-2 gene and induced essentially the same symptoms as those caused by Ltb1. Strains with either one of the two changes did not overcome the resistance as efficiently as Ltb1, although increased levels of multiplication were observed compared with the L strain. Results showed that both mutations are involved in the resistance-breaking property of Ltb1. Sequence analysis indicated that another resistance-breaking strain and its parent strain had two amino acid changes in the 30-kD protein: from Glu52 to Lys and from Glu133 to Lys. The fact that the amino acid changes occurred in or near the well conserved regions in the 30-kD protein suggests that the mechanism of Tm-2 resistance may be closely related to the fundamental function of the 30-kD protein, presumably in cell-to-cell movement.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=159785Documentos Relacionados
- Two amino acid substitutions in the tomato mosaic virus 30-kilodalton movement protein confer the ability to overcome the Tm-2(2) resistance gene in the tomato.
- The N gene of tobacco confers resistance to tobacco mosaic virus in transgenic tomato.
- Two concomitant base substitutions in the putative replicase genes of tobacco mosaic virus confer the ability to overcome the effects of a tomato resistance gene, Tm-1
- Function of the 30 kd protein of tobacco mosaic virus: involvement in cell-to-cell movement and dispensability for replication
- Nucleotide sequence of the 30K protein cistron of cowpea strain of tobacco mosaic virus.