Molecular Characterization of Erwinia carotovora hrpL, which Encodes an Alternate Sigma Factor
Many plant and animal pathogenic bacteria use the type III-secretion system to deliver virulence factors into host cells. It is becoming clear that the type III-secretion systems, in phytopathogenic and plant associated bacteria, are specifically used to transport Harpins, the elicitors of hypersensitive reaction (HR), as well as avirulence gene (avr) products, disease-specific (dsp) gene products and other accessory factors that could contribute to pathogenicity (3,1,8). It is, therefore, perhaps to be expected that hrp (gene for HR & pathogenicity), avr, dsp and other genes controlling host interaction are co-regulated by common signals, transcription factors including novel sigma factors, and post-transcription regulators.
KeywordsSerine Pseudomonas Cellulase Microbe Lactone
Unable to display preview. Download preview PDF.
Our research is supported by the National Science Foundation (grant MCB-9728505) and the Food for the 21st Century Program of the University of Missouri.
- 1.Bogdanove, A. J., Kim, J. F., Wei, Z., Kolchinsky, P., Charkowski, A. O., Conlin, A. K., Collmer, A., and Beer, S. V. 1998. Homology and functional similarity of an hrp-linked pathogenicity locus, dspEF, of Erwinia amylovora and the avirulence locus avrE of Pseudomonas syringae pathovar tomato. Proc. Natl. Acad. Sci. USA 95:1325–1330.PubMedCrossRefPubMedCentralGoogle Scholar
- 2.Chatterjee, A., Cui, Y., Liu, Y., Dumenyo, C. K., and Chatterjee, A. K. 1995. Inactivation of rsmA leads to overproduction of extracellular pectinases, cellulases, and proteases in Erwinia carotovora subsp. carotovora in the absence of the starvation/cell density-sensing signal, N-(3-oxohexanoyl)-L- homoserine lactone. Appl. Environ. Microbiol. 61:1959–1967.PubMedPubMedCentralGoogle Scholar
- 3.Collmer, A., Alfano, J. R., Anderson, D. M., Badel, J. L., Deng, W.-L., Fouts, D. E., Rehm, A. H., Rojas, C. M., Schneewind, O., and van Dijk, K. 2000. Hrp (type III) protein secretion and the virulence of Pseudomonas syringae and Erwinia chrysanthemi, p. 65–70. In P. J.G. M. de Wit, T. Bisseling, and W. Stiekema (ed.), Biology of Plant-Microbe Interactions, vol. 2. International Society for Molecular Plant-Microbe Interactions, St. Paul.Google Scholar
- 4.Cui, Y., Madi, L., Mukherjee, A., Dumenyo, C. K., and Chatterjee, A. K. 1996. The RsmA” mutants of Erwinia carotovora subsp. carotovora strain Ecc71 overexpress hrpN Ecc and elicit a hypersensitive reaction-like response in tobacco leaves. Mol. Plant-Microbe Interact. 9: 565–573.CrossRefGoogle Scholar
- 7.Huang, H. C., Lin. R. H., Chang, C. J., Collmer, A., and Deng, W. L. 1995. The complete hrp gene cluster of Pseudomonas syringae pv. syringae 61 includes two blocks of genes required for harpinPss secretion that are arranged colinearly with Yersinia ysc homologs. Mol. Plant-Microbe Interact. 8:733–746.CrossRefGoogle Scholar
- 10.Sambrook, J., E. F. Fritsch, and T. Maniatis. 1989. Molecular cloning: a laboratory manual., 2nd ed. Cold Spring Habor Laboratory Press., Cold Spring Habor, N.Y.Google Scholar
- 11.Wei, Z. M., Beer, S. V. 1995. hrpL activates Erwinia amylovora hrp gene transcription and is a member of the ECF subfamily of sigma factors. J. Bacterid. 177:6201–6210.Google Scholar
- 12.Xiao, Y., S. Heu, J. Yi, Y. Lu, and S. W. Hutcheson. 1994. Identification of a putative alternate sigma factor and characterization of a multicomponent regulatory cascade controlling the expression of Pseudomonas syringae pv. syringae Pss6l hro and hrmA genes. J. Bacteriol. 176:1025–1036.PubMedPubMedCentralGoogle Scholar