The molecular basis of pathogenicity, a virulence and resistance in the interaction between the fungal pathogen cladosporium fulvum and tomato

Información del proyecto

Identificador del acuerdo de subvención: BIOT0163

Proyecto cerrado

Fecha de inicio 1 Abril 1991

Fecha de finalización 31 Marzo 1994

Financiado con arreglo a

• Specific research and technological development programme (EEC) in the field of biotechnology (BRIDGE), 1990-1994

Coste total

Sin datos

Aportación de la UE

Sin datos

Coordinado por

WAGENINGEN UNIVERSITY
Netherlands

Objetivo

Genes conferring pathogenicity and avirulence in the fungal pathogen Cladosporium fulvum, the causal agent of tomato leaf mould, will be cloned. The function and regulation of those genes will be studied. The final objective is to clone the resistance genes in the tomato plant complementary to the fungal avirulence genes. Both resistance genes and avirulence genes can be exploited to obtain broad spectrum resistance to plant pathogens.
The objective of the project is the unraveling of the molecular basis of the plant-fungus interaction tomato-Cladosporium fulvum. Molecular characterization of gene-for-gene systems is in progress. Of the many bacterial genes and one fungal avirulence gene cloned to date none showed homology with other characterized genes. It is likely that the primary function of avirulence genes varies considerably. In some cases an avirulence gene may be so important for the pathogen that loss of it would be detrimental. A property all avirulence genes have in common is the antigenicity of their direct or indirect products. Through these products the pathogens are recognized by the host which responds by inducing a hypersensitive response (HR). The primary function of resistance genes is still a matter of speculation, as none have yet been cloned. Without knowing the primary function of either avirulence and resistance genes their secondary function (the induction ofHR by their interacting products) could perhaps be exploited to engineer transgenic disease-resistant plant.

Results of research to date include:
The first fungal avirulence gene, avr9, of C fulvum that fits a gene for gene relationship has been cloned. Cloning of another avirulence gene avr4 is within reach;
gene disruption has been successfully performed in C fulvum;
Transformation of C fulvum with the vector pAN8-1 has resulted in a number of mutants with reduced pathogenicity;
Two telomere sequences of C fulvum with the sequence TTAGGG have been isolated;
Tomato plants transgenic for chimeric beta 1,3-glucanase and chitinase genes have been obtained;
Apoplastic fluids of C fulvum-infected tomato leaves contain enzymes that release oligosaccharides from plant and fungal cell walls;
The cloning of a polygalacturonase inhibitor protein (PGIP) from Phaseolus vulgaris is completed.
Adopting an integrated approach involving biochemical, genetic and molecular techniques We shall investigate the structure, function and regulation of genes and gene products controlling the pathogenicity and race-specificity of C.fulvum and the resistance of tomato (lycopersicon esculentum). Two approaches will be employed. Firstly, the proteins isolated from apoplastic fluid of infected tomato leaves will be characterized. Their genes (whether fungal or plant) will be cloned and their functions determined by transformation of tomato or C.fulvum as appropriate. The model for this approach is the successful purification of the A9 fungal avirulence peptide and the cloning of its encoding gene. The role of apoplastic plant proteins such as 1,3-B-glucanases, chitinases and proteinaceous inhibitors of endopolygalacturonases as Well as oligosaccharides released by some of these enzymes will be studied. Also the structure and function of these oligosaccharides in inducing and enhancing defence responses will be objects of study. The second approach is an unbiassed search for fungal gene products controlling pathogenicity and avirulence. This Will involve characterization of non-pathogenic mutants created by integrative transformation and the use of promoter-probe vectors based on the B- glucuronidase reporter gene.

Ámbito científico (EuroSciVoc)

• ciencias naturales › ciencias biológicas › microbiología › micología
• ciencias naturales › ciencias biológicas › bioquímica › biomoléculas › proteínas › enzima

Programa(s)

• FP2-BRIDGE - Specific research and technological development programme (EEC) in the field of biotechnology (BRIDGE), 1990-1994

Tema(s)

Datos no disponibles

Convocatoria de propuestas

Datos no disponibles

Régimen de financiación

CSC - Cost-sharing contracts

Coordinador

WAGENINGEN UNIVERSITY

• Aportación de la UE: Sin datos
• Dirección: 9,Binnenhaven 9 ; 6709 PD WAGENINGEN ; Países Bajos
• Coste total: Sin datos

Participantes (5)

Landbouwuniversiteit Wageningen

Países Bajos

• Aportación de la UE: Sin datos
• Dirección: 2,Dreijenlaan ; 6703 HA Wageningen
• Coste total: Sin datos

Mogen International NV trading as ZENECA MOGEN

Países Bajos

• Aportación de la UE: Sin datos
• Dirección: 97,Einsteinweg ; 2333 CB Leiden
• Coste total: Sin datos

UNIVERSITY OF ROME "LA SAPIENZA"

Italia

• Aportación de la UE: Sin datos
• Dirección: Piazzale Aldo Moro 5 ; 00185 ROMA
• Coste total: Sin datos

University of East Anglia

Reino Unido

• Aportación de la UE: Sin datos
• Dirección: University Plain ; NR4 7TJ Norwich
• Coste total: Sin datos

University of Edinburgh

Reino Unido

• Aportación de la UE: Sin datos
• Dirección: Old College South Bridge ; EH1 1HN Edinburgh
• Coste total: Sin datos