1887

Abstract

Summary: is a pathogen of small grain crops and produces trichothecene mycotoxins in infected host tissue. The role of trichothecenes in the virulence of was previously investigated using trichothecene-non-producing mutants that were generated via transformation-mediated disruption of a gene () that encodes the first enzyme in the trichothecene biosynthetic pathway. The mutants were less virulent on some hosts than the wild-type strain from which they were derived. Here, we used two approaches to determine whether the reduced virulence of mutants was due specifically to disruption or to non-target effects caused by the transformation process. First, we generated a revertant from a disruption mutant by allowing the mutant to pass through the sexual phase of its life cycle. In approximately 2% of the resulting progeny the disrupted had reverted to wild-type; however, only one of three revertant progeny also regained the ability to produce trichothecenes. In the second approach, we complemented the mutation in a disruption mutant by transforming the mutant with a plasmid carrying a functional copy of In all transformants examined, the ability to produce trichothecenes was restored. The restoration of trichothecene production in the revertant progeny and in the complemented mutant was accompanied by restoration of wild-type or near wild-type levels of virulence on wheat seedlings (cultivar Wheaton). The results indicate that the reduced virulence of the mutants was caused by disruption of rather than non-target effects resulting from the transformation process. The results also provide further evidence that trichothecenes contribute to the virulence of plant-pathogenic fungi.

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1997-08-01
2021-04-21
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References

  1. Atanassov Z., Nakamura C., Mori N., Kaneda C., Kato H., Jin Y. Z., Yoshizawa T., Murai K. 1994; Mycotoxin production and pathogenicity of Fusarium species and wheat resistance to Fusarium head blight. Can J Bot 72:161–167
    [Google Scholar]
  2. Bowyer P., Clarke B. R., Lunness P., Daniels M. J., Osbourn A. E. 1995; Host range of a plant pathogenic fungus determined by a saponin detoxifying enzyme. Science 267:371–374
    [Google Scholar]
  3. Cambareri E. B., Jensen B. C., Schabtach E., Selker E. U. 1989; Repeat-induced G-C to A-T mutations in Neurospora. . Science 244:1571–1575
    [Google Scholar]
  4. Cook R. J. 1981; Fusarium diseases of wheat and other small grains in North America. . In Fusarium: Diseases, Biology and Taxonomy pp. 39–52 . Edited by Nelson P. E., Toussoun T. A., Cook R. J. University Park, PA: The Pennsylvania State University Press;
    [Google Scholar]
  5. Correll J. C., Klittich C. J. R., Leslie J. F. 1987; Nitrate nonutilizing mutants of Fusarium oxysporum and their use in vegetative compatibility tests. Phytopathology 77:1640–1646
    [Google Scholar]
  6. Corrick C. M., Hynes M. J. 1987; The nucleotide sequence of the amdS gene of Aspergillus nidulans and the molecular characterization of 5' mutations. Gene 53:63–71
    [Google Scholar]
  7. Desjardins A. E., Spencer G. F., Plattner R. D., Beremand M. N. 1989; Furanocoumarin phytoalexins, trichothecene toxins, and infection of Pastinaca sativa by Fusarium sporotrichioides. . Phytopathology 79:170–175
    [Google Scholar]
  8. Desjardins A. E., Hohn T. M., McCormick S. P. 1992; Effect of gene disruption of trichodiene synthase on the virulence of Gibberella pulicaris. . Mol Plant–Microbe Interact 5:214–222
    [Google Scholar]
  9. Desjardins A. E., Proctor R. H., Bai G., McCormick S. P., Shaner G., Buechley G., Hohn T. M. 1996; Reduced virulence of trichothecene antibiotic-nonproducing mutants of Gibberella zeae in wheat field tests. Mol Plant–Microbe Interact 9:775–781
    [Google Scholar]
  10. Herrmann M., Zocher R., Haese A. 1996; Effect of disruption of the enniatin synthetase gene on the virulence of Fusarium avenaceum. . Mol Plant–Microbe Interact 9:226–232
    [Google Scholar]
  11. Hohn T. M., Desjardins A. E. 1992; Isolation and gene disruption of the Tox5 gene encoding trichodiene synthase in Gibberella pulicaris. . Mol Plant–Microbe Interact 5:249–256
    [Google Scholar]
  12. Hohn T. M., VanMiddlesworth F. 1986; Purification and characterization of the sesquiterpene cyclase trichodiene synthetase from Fusarium sporotrichioides. . Arch Biochem Biophys 251:756–761
    [Google Scholar]
  13. Jarvis B. B. 1991; Macrocyclic trichothecenes. . In Mycotoxins and Phytoalexins pp. 361–421 . Edited by Sharma R. P., Salunkhe D. K. Boca Raton, FL: CRC Press;
    [Google Scholar]
  14. Jarvis B. B., Mokhtari-Rejali N., Schenkel E. P., Barros C. S., Matzenbacher N. I. 1991; Trichothecene mycotoxins from Brazilian Baccharis species. Phytochemistry 30:789–797
    [Google Scholar]
  15. Keller N. P., Bergstrom G. C., Yoder O. C. 1990; Effects of genetic transformation on fitness of Cochliobolus heterostrophus. . Phytopathology 80:1166–1173
    [Google Scholar]
  16. Klittich C. J. R., Leslie J. F. 1988; Nitrate reduction mutants of Fusarium moniliforme (Gibberella fujikuroi). Genetics 118:417–423
    [Google Scholar]
  17. Kommedahl T., Windels C. E. 1981; Root-, stalk-, and ear-infecting Fusarium species on corn in the USA. . In Fusarium: Diseases, Biology and Taxonomy pp. 94–103 . Edited by Nelson P. E., Toussoun T. A., Cook R. J. University Park, PA: The Pennsylvania State University Press;
    [Google Scholar]
  18. Miller B. L., Miller K. Y., Timberlake W. E. 1986; Direct and indirect gene replacements in Aspergillus nidulans. . Mol Cell Biol 5:1714–1721
    [Google Scholar]
  19. Nelson P. E., Pennypacker B. W., Toussoun T. A., Horst R. K. 1975; Fusarium stub dieback of carnation. Phytopathology 65:575–581
    [Google Scholar]
  20. Oliver R., Osbourn A. 1995; Molecular dissection of fungal phytopathogenicity. Microbiology 141:1–9
    [Google Scholar]
  21. Panaccione D. G., Scott-Craig J. S., Pocard J. A., Walton J. D. 1992; A cyclic peptide synthetase gene required for pathogenicity of the fungus Cochliobolus carbonum on maize. Proc Natl Acad Sci USA 89:6590–6594
    [Google Scholar]
  22. Proctor R. H., Hohn T. M., McCormick S. P. 1995; Reduced virulence of Gibberella zeae caused by disruption of a trichothecene toxin biosynthectic gene. Mol Plant–Microbe Interact 8:593–601
    [Google Scholar]
  23. Rhounim L., Rossignol J. L., Faugeron G. 1992; Epimutation of repeated genes in Ascobolus immersus. . EMBO J 11:4451–4457
    [Google Scholar]
  24. Rogers L. M., Flaishman M. A., Kolattukudy P. E. 1994; Cutinase gene disruption in Fusarium solani f. sp. pisi decreases its virulence on pea. Plant Cell 6:935–945
    [Google Scholar]
  25. Salch Y. P., Beremand M. N. 1993; Gibberella pulicaris transformants: state of transforming DNA during asexual and sexual growth. Curr Genet 23:343–350
    [Google Scholar]
  26. Sambrook J., Fritsch E. F., Maniatis T. 1989 Molecular Cloning: A Laboratory Manual Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
    [Google Scholar]
  27. Selker E. U., Cambareri E. B., Jensen B. C., Haack K. R. 1987; Rearrangement of duplicated DNA in specialized cells of Neurospora. . Cell 51:741–752
    [Google Scholar]
  28. Sharma R. P., Kim Y. W. 1991; Trichothecenes. . In Mycotoxins and Phytoalexins pp. 339–359 . Edited by Sharma R. P., Salunkhe D. K. Boca Raton, FL: CRC Press;
    [Google Scholar]
  29. Stahl D. J., Theuerkauf A., Heitefuss R., Schafer W. 1994; Cutinase of Nectria haematococca (Fusarium solani f. sp. pisi) is not required for fungal virulence or organ specificity on pea. Mol Plant–Microbe Interact 7:713–725
    [Google Scholar]
  30. Talbot N. J., Ebbole D. J., Hamer J. E. 1993; Identification and characterization of MPG1, a gene involved in pathogenicity from the rice blast fungus Magnaporthe grisea. . Plant Cell 5:1575–1590
    [Google Scholar]
  31. Talbot N. J., Kershaw M. J., Wakley G. E., deVries O. M. H., Wessels J. G. H., Hamer J. E. 1996; MPG1 encodes a fungal hydrophobin involved in surface interactions during infection-related development of Magnaporthe grisea. . Plant Cell 8:985–999
    [Google Scholar]
  32. Tuite J. 1969 Plant Pathological Methods: Fungi and Bacteria Minneapolis, MN: Burgess Publishing Company;
    [Google Scholar]
  33. Turgeon B. G., Garber R. C., Yoder O. C. 1987; Development of a fungal transformation system based on selection of sequences with promoter activity. Mol Cell Biol 7:3297–3305
    [Google Scholar]
  34. VanEtten H. D., Sandrock R. W., Wasmann C. C., Soby S. D., McCluskey K., Wang P. 1995; Detoxification of phytoanticipins and phytoalexins by phytopathogenic fungi. Can J Bot73 suppl 1:S518–S525
    [Google Scholar]
  35. Wang Y. Z., Miller J. D. 1988; Effects of Fusarium graminearum metabolites on wheat tissue in relation to Fusarium head blight resistance. J Phytopathol 122:118–125
    [Google Scholar]
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