期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1998
卷号：95
期号：15
页码：9014-9018
DOI：10.1073/pnas.95.15.9014
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The interaction between tomato and its fungal pathogen Cladosporium fulvum complies with the gene-for-gene system, in which specific recognition of fungal proteins by plant genotypes with matching resistance genes results in host resistance. Two proteins, ECP1 and ECP2, secreted by C. fulvum during infection, are required for full virulence of the fungus on tomato. We chose the most important virulence factor, ECP2, for a targeted search for hypersensitive response (HR)-based resistance among a collection of tomato genotypes. By screening with recombinant potato virus X that expresses the Ecp2 gene, we identified four lines that respond with HR toward ECP2. The capacity to recognize ECP2 and induce HR is sufficient to confer resistance in tomato against C. fulvum producing ECP2. Resistance is based on a single dominant gene, which we have designated Cf-ECP2, for resistance to C. fulvum through recognition of ECP2. Accordingly, an Ecp2-minus strain created by gene replacement is pathogenic on Cf-ECP2 plants. However, due to lack of ECP2 the mutant strain is only weakly virulent. All strains of a worldwide collection of C. fulvum strains that were tested were found to produce a HR-inducing ECP2 protein. Because the Cf-ECP2 gene operates through recognition of an important virulence factor, we expect it will confer durable resistance against C. fulvum. A similar targeted approach should allow the discovery of new valuable resistance genes in other pathosystems.
