The AVR2-SIX5 gene pair is required to activate I-2-mediated immunity in tomato.
New Phytol
; 208(2): 507-18, 2015 Oct.
Article
en En
| MEDLINE
| ID: mdl-25967461
ABSTRACT
Plant-invading microbes betray their presence to a plant by exposure of antigenic molecules such as small, secreted proteins called 'effectors'. In Fusarium oxysporum f. sp. lycopersici (Fol) we identified a pair of effector gene candidates, AVR2-SIX5, whose expression is controlled by a shared promoter. The pathogenicity of AVR2 and SIX5 Fol knockouts was assessed on susceptible and resistant tomato (Solanum lycopersicum) plants carrying I-2. The I-2 NB-LRR protein confers resistance to Fol races carrying AVR2. Like Avr2, Six5 was found to be required for full virulence on susceptible plants. Unexpectedly, each knockout could breach I-2-mediated disease resistance. So whereas Avr2 is sufficient to induce I-2-mediated cell death, Avr2 and Six5 are both required for resistance. Avr2 and Six5 interact in yeast two-hybrid assays as well as in planta. Six5 and Avr2 accumulate in xylem sap of plants infected with the reciprocal knockouts, showing that lack of I-2 activation is not due to a lack of Avr2 accumulation in the SIX5 mutant. The effector repertoire of a pathogen determines its host specificity and its ability to manipulate plant immunity. Our findings challenge an oversimplified interpretation of the gene-for-gene model by showing requirement of two fungal genes for immunity conferred by one resistance gene.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
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Proteínas Fúngicas
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Solanum lycopersicum
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Inmunidad de la Planta
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Genes Fúngicos
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
New Phytol
Asunto de la revista:
BOTANICA
Año:
2015
Tipo del documento:
Article
País de afiliación:
Países Bajos