Characterization and Function of Bacterial Avirulence Genes
Considerable progress has occurred in the cloning and characterization of avirulence genes from viral and bacterial pathogens. All of the avirulence genes thus far cloned behave as single dominant alleles and encode unique protein products. Nevertheless, with one noteworthy exception, the functions of avirulence genes in the pathogens that harbor them are not known. The hypersensitive reaction (HR) in plants carrying the complementary avirulence gene, however, appears to be determined by elicitors— either primary avirulence gene protein products or metabolites arising from their catalytic activity. Since this topic has already been reviewed in depth (Keen et al., 1990; Keen, 1990), in this paper, I will concentrate only on the most recent information.
KeywordsHypersensitive Reaction Tobacco Mosaic Virus Plant Pathol Coat Protein Gene Disease Resistance Gene
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- De Wit, P.J.G.M., Hofman, A.E., Velthuis, G.C.M., and Kuc, J.A., 1985, Isolation and characterization of an elicitor of necrosis isolated from intercellular fluids of compatible interactions of Cladosporium fulvum (syn. Fulvia fulva) and tomato, Plant Physiol. 77:642–647.Google Scholar
- Ellingboe, A.H., 1984, Genetics of host-parasite relations: an essay, Adv. Plant Pathol. 2:131–151.Google Scholar
- Flor, H.H., 1942, Inheritance of pathogenicity in Melampsora lini, Phytopathology 32:653–669.Google Scholar
- Gabriel, D.W., and Rolfe, B.G., 1990, Working models of specific recognition in plant-microbe interactions, Annu. Rev. Phytopathol. (in press).Google Scholar
- Keen, N.T., 1976, Specific elicitors of phytoalexin production: determinants of race specificity? In Biochemistry and Cytology of Plant-Parasite Interaction, pp. 84–93, (Tomiyama, K. et al., eds.), Kodansha Ltd., Tokyo.Google Scholar
- Keen, N.T., and Buzzell, R.I., 1990, New disease resistance genes in soybean against Pseudomonas syringae pv. glycinea: evidence that one of them interacts with a bacterial elicitor. Theor. Appl. Genet. (in press).Google Scholar
- Keen, N.T., and Dawson, W.O., 1990, Pathogen avirulence genes and elicitors of plant defense. In Genes Involved in Plant Defense (Boller, W. and Meins, F. eds.), Springer-Verlag, New York. (in press).Google Scholar
- Keen, N.T., Tamaki, S., Kobayashi, D., Gerhold, D., Stayton, M., Shen, H., Gold, S., Lorang, J., Thordal-Christensen, H., Dahlbeck, D., and Staskawicz, B., 1990, Bacteria expressing avirulence gene D produce a specific elicitor of the soybean hypersensitive reaction, Molec. Plant-Microbe Interact. 3:112–121.CrossRefGoogle Scholar
- Tamaki, S., Dahlbeck, D., Staskawicz, B., and Keen, N.T., 1988, Characterization and expression of two avirulence genes cloned from Pseudomonas syringae pv. glycinea. J. Bacteriol. 170:4846–4854.Google Scholar
- Vivian, A., Atherton, G.T., Bevan, J.R., Crute, I.R., Mur, L.A.J., and Taylor, J.D., 1989, Isolation and characterization of cloned DNA conferring specific avirulence in Pseudomonas syringae pv. pisi to pea (Pisum sativum) cultivars, which possess the resistance allele, R2, Physiol. Molec. Plant Pathol., 34:335–344.CrossRefGoogle Scholar