Breaking the DNA-binding code of Ralstonia solanacearum TAL effectors provides new possibilities to generate plant resistance genes against bacterial wilt disease.
New Phytol
; 199(3): 773-86, 2013 Aug.
Article
em En
| MEDLINE
| ID: mdl-23692030
ABSTRACT
Ralstonia solanacearum is a devastating bacterial phytopathogen with a broad host range. Ralstonia solanacearum injected effector proteins (Rips) are key to the successful invasion of host plants. We have characterized Brg11(hrpB-regulated 11), the first identified member of a class of Rips with high sequence similarity to the transcription activator-like (TAL) effectors of Xanthomonas spp., collectively termed RipTALs. Fluorescence microscopy of in planta expressed RipTALs showed nuclear localization. Domain swaps between Brg11 and Xanthomonas TAL effector (TALE) AvrBs3 (avirulence protein triggering Bs3 resistance) showed the functional interchangeability of DNA-binding and transcriptional activation domains. PCR was used to determine the sequence of brg11 homologs from strains infecting phylogenetically diverse host plants. Brg11 localizes to the nucleus and activates promoters containing a matching effector-binding element (EBE). Brg11 and homologs preferentially activate promoters containing EBEs with a 5' terminal guanine, contrasting with the TALE preference for a 5' thymine. Brg11 and other RipTALs probably promote disease through the transcriptional activation of host genes. Brg11 and the majority of homologs identified in this study were shown to activate similar or identical target sequences, in contrast to TALEs, which generally show highly diverse target preferences. This information provides new options for the engineering of plants resistant to R. solanacearum.
Palavras-chave
AvrBs3 (avirulence protein triggering Bs3 resistance); Brg11(hrpB-regulated 11); GMI1000; Ralstonia solanacearum; Ralstonia transcription activator-like effector (TALE)-like (RTL); designer transcription activator-like effector (TALE); repeat variable diresidue (RVD); transcription activator-like (TAL) effectors
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Doenças das Plantas
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Proteínas de Bactérias
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DNA Bacteriano
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Genes de Plantas
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Ralstonia solanacearum
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Resistência à Doença
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article