Abstract
The inoculation of tobacco (Nicotiana tabacum L.) suspension cells with bacterial pathogens that elicit the hypersensitive response (HR) in leaves has been shown to elicit production of active oxygen. This response occurs in two phases, the second of which occurs 1 to 3 h after bacterial addition and is unique to HR-causing interactions. The relationship between the phase II active oxygen response and the HR was characterized using Pseudomonas syringae pv syringae and P. fluorescens (pHIR11), which contains a cosmid clone of the hrp/hrm region from P. syringae pv syringae. TnphoA mutations in complementation groups II through XIII of the hrp cluster blocked the phase II active oxygen response, whereas mutations in the group I hrmA locus did not affect phase II. Despite the normal active oxygen response, bacteria with mutations in the hrmA region did not cause the HR in intact tobacco leaves nor did they induce hypersensitive cell death in cell suspensions. The data indicate that the bacteria do not require the hrmA region to elicit active oxygen production, but a full and intact hrp/hrm region is required to elicit hypersensitive cell death. Therefore, the phase II active oxygen response does not directly cause hypersensitive cell death nor is the response itself sufficient to trigger the HR.
Full Text
The Full Text of this article is available as a PDF (490.6 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Baker C. J., Harmon G. L., Glazener J. A., Orlandi E. W. A Noninvasive Technique for Monitoring Peroxidative and H2O2-Scavenging Activities during Interactions between Bacterial Plant Pathogens and Suspension Cells. Plant Physiol. 1995 May;108(1):353–359. doi: 10.1104/pp.108.1.353. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Baker C. J., Orlandi E. W., Mock N. M. Harpin, An Elicitor of the Hypersensitive Response in Tobacco Caused by Erwinia amylovora, Elicits Active Oxygen Production in Suspension Cells. Plant Physiol. 1993 Aug;102(4):1341–1344. doi: 10.1104/pp.102.4.1341. [DOI] [PMC free article] [PubMed] [Google Scholar]
- He S. Y., Huang H. C., Collmer A. Pseudomonas syringae pv. syringae harpinPss: a protein that is secreted via the Hrp pathway and elicits the hypersensitive response in plants. Cell. 1993 Jul 2;73(7):1255–1266. doi: 10.1016/0092-8674(93)90354-s. [DOI] [PubMed] [Google Scholar]
- Huang H. C., He S. Y., Bauer D. W., Collmer A. The Pseudomonas syringae pv. syringae 61 hrpH product, an envelope protein required for elicitation of the hypersensitive response in plants. J Bacteriol. 1992 Nov;174(21):6878–6885. doi: 10.1128/jb.174.21.6878-6885.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Huang H. C., Lin R. H., Chang C. J., Collmer A., Deng W. L. 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. 1995 Sep-Oct;8(5):733–746. doi: 10.1094/mpmi-8-0733. [DOI] [PubMed] [Google Scholar]
- Huang H. C., Schuurink R., Denny T. P., Atkinson M. M., Baker C. J., Yucel I., Hutcheson S. W., Collmer A. Molecular cloning of a Pseudomonas syringae pv. syringae gene cluster that enables Pseudomonas fluorescens to elicit the hypersensitive response in tobacco plants. J Bacteriol. 1988 Oct;170(10):4748–4756. doi: 10.1128/jb.170.10.4748-4756.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Legendre L., Rueter S., Heinstein P. F., Low P. S. Characterization of the Oligogalacturonide-Induced Oxidative Burst in Cultured Soybean (Glycine max) Cells. Plant Physiol. 1993 May;102(1):233–240. doi: 10.1104/pp.102.1.233. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Levine A., Tenhaken R., Dixon R., Lamb C. H2O2 from the oxidative burst orchestrates the plant hypersensitive disease resistance response. Cell. 1994 Nov 18;79(4):583–593. doi: 10.1016/0092-8674(94)90544-4. [DOI] [PubMed] [Google Scholar]