Skip to main content
NCBI home page
Plant Physiology logoLink to Plant Physiology
. 1987 Jul;84(3):670–676. doi: 10.1104/pp.84.3.670

Dissipation of the Membrane Potential in Susceptible Corn Mitochondria by the Toxin of Helminthosporium maydis, Race T, and Toxin Analogs 1

Marcia J Holden 1,2, Heven Sze 1
PMCID: PMC1056648  PMID: 16665500

Abstract

We have tested directly the effect of Helminthosporium maydis T (Hmt) toxin and various analogs on the membrane potential formed in mitochondria isolated from a Texas (T) cytoplasmic male-sterile and a normal (N) corn. ATP, malate or succinate generated a membrane potential (negative inside) as monitored by the absorbance change of a cationic dye, safranine. The relative membrane potential (Δψ) could also be detected indirectly as 45Ca2+ uptake. Hmt toxin added to T mitochondria dissipated the steady state Δψ similar to addition of a protonophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP). Toxin analogs (Cpd XIII: C41H68O12 and Cpd IV: C25H44O6), reduced native toxin (RT2C: C41H84O13) and Pm toxin (band A: C33H60O8, produced by the fungus, Phyllosticta maydis) were effective in dissipating Δψ and decreasing Ca2+ uptake with the following order: Pm (100) » HmT (23-30) > Cpd XIII (11-25) » RT2C (0-4−1.8) > Cpd IV (0.2−1.0). In contrast, the toxins and analogs had no effect on Δψ formed in N mitochondria. The striking similarities of the HmT toxin (band 1: C41H68O13) and Cpd XIII on T mitochondrial activities provide strong evidence supporting the correctness of the polyketol structure assigned to the native toxin. Since the Δψ in energized mitochondria is caused mainly by the electrogenic extrusion of H+, the results support the idea that HmT toxin increases membrane permeability of T mitochondria to H+. The host specificity of the toxin suggests that an interaction with unique target site(s) on the inner mitochondrial membrane of T corn causes H+ leakage.

Full text

PDF
670

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Akerman K. E., Moore A. L. Phosphate dependent, ruthenium red insensitive CA2+ uptake in mung bean mitochondria. Biochem Biophys Res Commun. 1983 Aug 12;114(3):1176–1181. doi: 10.1016/0006-291x(83)90686-1. [DOI] [PubMed] [Google Scholar]
  2. Bednarski M. A., Izawa S., Scheffer R. P. Reversible Effects of Toxin from Helminthosporium maydis Race T on Oxidative Phosphorylation by Mitochondria from Maize. Plant Physiol. 1977 Apr;59(4):540–545. doi: 10.1104/pp.59.4.540. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bervillé A., Ghazi A., Charbonnier M., Bonavent J. F. Effects of Methomyl and Helminthosporium maydis Toxin on Matrix Volume, Proton Motive Force, and NAD Accumulation in Maize (Zea mays L.) Mitochondria. Plant Physiol. 1984 Oct;76(2):508–517. doi: 10.1104/pp.76.2.508. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
  5. Day D. A., Bertagnolli B. L., Hanson J. B. The effect of calcium on the respiratory responses of corn mitochondria. Biochim Biophys Acta. 1978 May 10;502(2):289–297. doi: 10.1016/0005-2728(78)90050-6. [DOI] [PubMed] [Google Scholar]
  6. Gregory P., Earle E. D., Gracen V. E. Effects of Purified Helminthosporium maydis Race T Toxin on the Structure and Function of Corn Mitochondria and Protoplasts. Plant Physiol. 1980 Sep;66(3):477–481. doi: 10.1104/pp.66.3.477. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Holden M. J., Sze H. Helminthosporium maydis T Toxin Increased Membrane Permeability to Ca in Susceptible Corn Mitochondria. Plant Physiol. 1984 May;75(1):235–237. doi: 10.1104/pp.75.1.235. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Kimber A., Sze H. Helminthosporium maydis T Toxin Decreased Calcium Transport into Mitochondria of Susceptible Corn. Plant Physiol. 1984 Apr;74(4):804–809. doi: 10.1104/pp.74.4.804. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Klein R. R., Koeppe D. E. Mode of Methomyl and Bipolaris maydis (race T) Toxin in Uncoupling Texas Male-Sterile Cytoplasm Corn Mitochondria. Plant Physiol. 1985 Apr;77(4):912–916. doi: 10.1104/pp.77.4.912. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Miller R. J., Koeppe D. E. Southern corn leaf blight: susceptible and resistant mitochondria. Science. 1971 Jul 2;173(3991):67–69. doi: 10.1126/science.173.3991.67. [DOI] [PubMed] [Google Scholar]
  11. Moore A. L., Bonner W. D. Measurements of membrane potentials in plant mitochondria with the safranine method. Plant Physiol. 1982 Nov;70(5):1271–1276. doi: 10.1104/pp.70.5.1271. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Neuburger M., Douce R. Effect of bicarbonate and oxaloacetate on malate oxidation by spinach leaf mitochondria. Biochim Biophys Acta. 1980 Feb 8;589(2):176–189. doi: 10.1016/0005-2728(80)90036-5. [DOI] [PubMed] [Google Scholar]
  13. Nicholls D., Akerman K. Mitochondrial calcium transport. Biochim Biophys Acta. 1982 Sep 1;683(1):57–88. doi: 10.1016/0304-4173(82)90013-1. [DOI] [PubMed] [Google Scholar]
  14. Payne G., Kono Y., Daly J. M. A Comparison of Purified Host Specific Toxin from Helminthosporium maydis, Race T, and Its Acetate Derivative on Oxidation by Mitochondria from Susceptible and Resistant Plants. Plant Physiol. 1980 May;65(5):785–791. doi: 10.1104/pp.65.5.785. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Pham H. N., Gregory P. Loss of Sensitivity to Helminthosporium maydis Race T Toxin during Aging of Mitochondria Isolated from Texas Cytoplasm Corn. Plant Physiol. 1980 Jun;65(6):1173–1175. doi: 10.1104/pp.65.6.1173. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Suzuki Y., Danko S. J., Daly J. M., Kono Y., Knoche H. W., Takeuchi S. Comparison of Activities of the Host-Specific Toxin of Helminthosporium maydis, Race T, and a Synthetic C(41) Analog. Plant Physiol. 1983 Oct;73(2):440–444. doi: 10.1104/pp.73.2.440. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES