Abstract
Victorin, the pathotoxin from the host-specific pathogen, Helminthosporium victoriae, promotes the growth of coleoptile segments when given at concentrations that are high but which still show selective effects on susceptible and resistant tissue. The latent period in the growth response of both susceptible and resistant tissue is about 3.6 minutes compared to 11.0 minutes in the response of these tissues to auxin. The victorinpromoted rate of elongation of 8-millimeter segments is about 0.2 millimeter per hour in susceptible tissue and about 0.1 millimeter per hour in resistant tissue compared to about 0.4 millimeter per hour in response to auxin. At low concentrations, the toxin has no growth-promoting effect in either susceptible or resistant coleoptile segments. Over a wide range of concentrations, victorin inhibits the growth response of susceptible tissue to auxin completely while having no effect on the response of resistant tissue to auxin.
Victorin induces solute leakage in coleoptile tissue of susceptible but not resistant varieties of Avena. In susceptible tissue, solute leakage begins about 2 minutes after the addition of toxin and continues for at least 4 hours.
The rapidity and close correlation of toxin effects on membrane permeability (2 minutes) and on growth (3.6 minutes) suggest the possibility that the initial action of victorin in both cases may be at the cell surface, perhaps the plasmalemma.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Evans M. L., Ray P. M., Reinhold L. Induction of coleoptile elongation by carbon dioxide. Plant Physiol. 1971 Mar;47(3):335–341. doi: 10.1104/pp.47.3.335. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Evans M. L., Ray P. M. Timing of the auxin response in coleoptiles and its implications regarding auxin action. J Gen Physiol. 1969 Jan;53(1):1–20. doi: 10.1085/jgp.53.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hardin J. W., Cherry J. H., Morré D. J., Lembi C. A. Enhancement of RNA polymerase activity by a factor released by auxin from plasma membrane. Proc Natl Acad Sci U S A. 1972 Nov;69(11):3146–3150. doi: 10.1073/pnas.69.11.3146. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Luke H. H., Warmke H. E., Hanchey P. Effects of the pathotoxin victorin on ultrastructure of root and leaf tissue of Avena species. Phytopathology. 1966 Oct;56(10):1178–1183. [PubMed] [Google Scholar]
- Lüttge U., Higinbotham N., Pallaghy C. K. Electrochemical evidence of specific action of indole acetic acid on membranes in Mnium leeaves. Z Naturforsch B. 1972 Oct;27(10):1239–1242. doi: 10.1515/znb-1972-1024. [DOI] [PubMed] [Google Scholar]
- Meehan F., Murphy H. C. A New Helminthosporium Blight of Oats. Science. 1946 Nov 1;104(2705):413–414. doi: 10.1126/science.104.2705.413. [DOI] [PubMed] [Google Scholar]
- Meehan F., Murphy H. C. Differential Phytotoxicity of Metabolic By-Products of Helminthosporium victoriae. Science. 1947 Sep 19;106(2751):270–271. doi: 10.1126/science.106.2751.270-a. [DOI] [PubMed] [Google Scholar]
- NELSON L. S. KAMPAC. J Kans Med Soc. 1964 Dec;65:602–603. [PubMed] [Google Scholar]
- PRINGLE R. B., BRAUN A. C. Constitution of the toxin of Helminthosporium victoriae. Nature. 1958 Apr 26;181(4617):1205–1206. doi: 10.1038/1811205a0. [DOI] [PubMed] [Google Scholar]
- Rayle D. L., Cleland R. Enhancement of wall loosening and elongation by Acid solutions. Plant Physiol. 1970 Aug;46(2):250–253. doi: 10.1104/pp.46.2.250. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SACHER J. A., GLASZIOU K. T. Effects of auxins on membrane permeability and pectic substances in bean endocarp. Nature. 1959 Mar 14;183(4663):757–758. doi: 10.1038/183757b0. [DOI] [PubMed] [Google Scholar]
- Samaddar K. R., Scheffer R. P. Effect of the Specific Toxin in Helminthosporium victoriae on Host Cell Membranes. Plant Physiol. 1968 Jan;43(1):21–28. doi: 10.1104/pp.43.1.21. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stahl C., Vanderhoef L. N., Siegel N. Fusarium tricinctum T-2 Toxin Inhibits Auxin-promoted Elongation in Soybean Hypocotyl. Plant Physiol. 1973 Dec;52(6):663–666. doi: 10.1104/pp.52.6.663. [DOI] [PMC free article] [PubMed] [Google Scholar]
