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. 1985 Oct;79(2):468–473. doi: 10.1104/pp.79.2.468

Association between Symptom Development and Inhibition of Ornithine Carbamoyltransferase in Bean Leaves Treated with Phaseolotoxin

John G Turner 1,1, Robin E Mitchell 1
PMCID: PMC1074908  PMID: 16664433

Abstract

The chlorosis symptom that characterizes the halo blight disease of Phaseolus vulgaris L. is caused by phaseolotoxin produced by the plant pathogenic bacterium Pseudomonas syringae pv phaseolicola. Phaseolotoxin is hydrolyzed by plant peptidases to Nδ(N′-sulpho-diaminophosphinyl) -l-ornithine which also causes chlorosis and is reported to be an irreversible inhibitor of ornithine carbamoyltransferase (OCTase). We have examined the hypothesis that inhibition of OCTase is the primary action of phaseolotoxin that leads to chlorosis.

Chlorotic spots appeared on the primary leaves of P. vulgaris seedlings during the 2 days following leaf prick application of a minimum of 30 picomole phaseolotoxin. OCTase in extracts of the lesions was reduced to 20%, or less, of the activity in controls. Four hours after the application of phaseolotoxin the concentration of free ornithine increased more than 2-fold. Other amino acids, especially glutamine and asparagine—but not arginine—increased later. Chlorophyll remained at a constant level in the phaseolotoxin-treated tissue and the appearance of chlorosis was due to the increase in chlorophyll in the surrounding unaffected tissue.

Clear halo symptoms developed only on primary leaves of the youngest seedlings (treated 6-7 days after germination). Lesions did not develop on primary leaves of seedlings more than 14 days old, in which the chlorophyll concentration had reached a maximum. OCTase also was inhibited in the symptomless tissue from older leaves treated with phaseolotoxin, but there was no accumulation of amino acids, including ornithine. A single appliction of 200 nanomoles arginine resulted in the complete regreening of the chlorosis caused by phaseolotoxin. Soluble protein was lower in the chlorotic tissue than in the controls, but increased to greater than the control value following the appliction of arginine. These results suggest that phaseolotoxin-induced chlorosis results from reduced chlorophyll synthesis that is associated with arginine-starvation in the tissue where OCTase is inhibited.

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Selected References

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  1. Armond P. A., Staehelin L. A., Arntzen C. J. Spatial relationship of photosystem I, photosystem II, and the light-harvesting complex in chloroplast membranes. J Cell Biol. 1977 May;73(2):400–418. doi: 10.1083/jcb.73.2.400. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Arnon D. I. COPPER ENZYMES IN ISOLATED CHLOROPLASTS. POLYPHENOLOXIDASE IN BETA VULGARIS. Plant Physiol. 1949 Jan;24(1):1–15. doi: 10.1104/pp.24.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bauer A., Urquhart A. A., Joy K. W. Amino Acid metabolism of pea leaves: diurnal changes and amino Acid synthesis from N-nitrate. Plant Physiol. 1977 May;59(5):915–919. doi: 10.1104/pp.59.5.915. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bieleski R. L., Turner N. A. Separation and estimation of amino acids in crude plant extracts by thin-layer electrophoresis and chromatography. Anal Biochem. 1966 Nov;17(2):278–293. doi: 10.1016/0003-2697(66)90206-5. [DOI] [PubMed] [Google Scholar]
  5. Gasson M. J. Indicator technique for antimetabolic toxin production by phytopathogenic species of pseudomonas. Appl Environ Microbiol. 1980 Jan;39(1):25–29. doi: 10.1128/aem.39.1.25-29.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Jacques S., Sung Z. R. Regulation of pyrimidine and arginine biosynthesis investigated by the use of phaseolotoxin and 5-Fluorouracil. Plant Physiol. 1981 Feb;67(2):287–291. doi: 10.1104/pp.67.2.287. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Kwok O. C., Ako H., Patil S. S. Inactivation of bean ornithine carbamoyltransferase by phaseotoxin: effect of phosphate. Biochem Biophys Res Commun. 1979 Aug 28;89(4):1361–1368. doi: 10.1016/0006-291x(79)92159-4. [DOI] [PubMed] [Google Scholar]
  8. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  9. Mitchell R. E., Bieleski R. L. Involvement of phaseolotoxin in halo blight of beans: transport and conversion to functional toxin. Plant Physiol. 1977 Nov;60(5):723–729. doi: 10.1104/pp.60.5.723. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Patil S. S., Tam L. Q. Mode of Action of the Toxin from Pseudomonas phaseolicola: I. Toxin Specificity, Chlorosis, and Ornithine Accumulation. Plant Physiol. 1972 May;49(5):803–807. doi: 10.1104/pp.49.5.803. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Redgwell R. J. Fractionation of plant extracts using ion-exchange Sephadex. Anal Biochem. 1980 Sep 1;107(1):44–50. doi: 10.1016/0003-2697(80)90489-3. [DOI] [PubMed] [Google Scholar]
  12. Smith A. G., Rubery P. H. Investigation of the Mechanism of Action of a Chlorosis-Inducing Toxin Produced by Pseudomonas phaseolicola. Plant Physiol. 1982 Oct;70(4):932–938. doi: 10.1104/pp.70.4.932. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Tam L. Q., Patil S. S. Mode of Action of the Toxin from Pseudomonas phaseolicola: II. Mechanism of Inhibition of Bean Ornithine Carbamoyltransferase. Plant Physiol. 1972 May;49(5):808–812. doi: 10.1104/pp.49.5.808. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Templeton M. D., Mitchell R. E., Sullivan P. A., Shepherd M. G. The inactivation of ornithine transcarbamoylase by N delta-(N'-sulpho-diaminophosphinyl)-L-ornithine. Biochem J. 1985 Jun 1;228(2):347–352. doi: 10.1042/bj2280347. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Templeton M. D., Sullivan P. A., Shepherd M. G. The inhibition of ornithine transcarbamoylase from Escherichia coli W by phaseolotoxin. Biochem J. 1984 Dec 1;224(2):379–388. doi: 10.1042/bj2240379. [DOI] [PMC free article] [PubMed] [Google Scholar]

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