Molecular characerization of the interaction between the fungal pathogen Cladosporium fulvum and tomato |
| |
| Authors: | Guy Honée Guido F J M Van den Ackerveken Henk W J Van den Broek Ton J Cozijnsen Matthieu H A J Joosten Mirian Kooman-Gersmann Jacques Vervoort Ralph Vogelsang Paul Vossen Jos P Wubben Pierre J G M De Wit |
| |
| Institution: | (1) Department of Phytopathology, Wageningen Agricultural University, Binnenhaven 8, 6709 PD Wageningen, The Netherlands;(2) Department of Genetics, Wageningen Agricultural University, Dreijenlaan 2, 6703 HA Wageningen, The Netherlands;(3) Department of Biochemistry, Wageningen Agricultural University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands;(4) Present address: Institut des Sciences Végétales, CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette, Frace |
| |
| Abstract: | The fungus Cladosprium fulvum is a biotrophic leaf pathogen of tomato. The fungus develops in the intercellular space without forming specialized feeding structures and does not affect the leaf tissue. The outcome of the C. fulvum-tomato interaction can be described by the gene-for-gene model. Failure of infection is expressed by a hypersensitive response. Two fungal proteins, ECP1 and ECP2, have been isolated and their corresponding genes have been cloned. In a compatible interaction including many physiological races ECP1 and ECP2 are highly produced and a role in pathogenicity is suggestive. The ecp1 gene shows some homology with tumor necrosis factor receptors (TNFRs) while the ecp2 gene shows no homology with sequences known in data bases. However, disruption of one of the two genes showed no reduced pathogenicity of the fungus. Two race-specific elicitors, AVR4 and AVR9, have been isolated and their corresponding genes have been cloned. The avirulence genes Avr4 and Avr9 are only present in C. fulvum avirulent on Cf-4 and Cf-9 cultivars, respectively. The expression of these two genes is, like the expression of the ecp genes, highly induced when the fungus grows in planta. Disruption of the Avr9 gene in wild type avirulent races leads to virulence on tomato genotypes carrying the complementary resistance gene Cf-9. A single base-pair change in the avirulence gene Avr4 leads to virulence on tomato genotypes carrying the Cf-4 resistance gene. Isolation, characterization and possible function of ECP1, ECP2, AVR4, and AVR9 will be discussed. |
| |
| Keywords: | Avirulence defense response high affinity binding sites pathogenicity race specific elicitor structure-function analysis transgenic plants |
| 本文献已被 SpringerLink 等数据库收录！ |
|
