Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-25T16:13:28.214Z Has data issue: false hasContentIssue false

Factors influencing the herbicidal activity of Nep1, a fungal protein that induces the hypersensitive response in Centaurea maculosa

Published online by Cambridge University Press:  20 January 2017

Ronald Collins
Affiliation:
Weed Science Laboratory, USDA/ARS, Beltsville Agricultural Research Center, Beltsville, MD 20705
James D. Anderson
Affiliation:
Weed Science Laboratory, USDA/ARS, Beltsville Agricultural Research Center, Beltsville, MD 20705

Abstract

The fungal protein Nep1, produced by Fusarium oxysporum f. sp. erythroxyli in liquid culture, caused extensive necrosis to Centaurea maculosa when water solutions of Nep1 (5 µg ml−1) and an organosilicone surfactant (1,1,1,3,5,5,5-heptamethyltrisiloxanyl propyl-methoxy-poly[ethylene oxide]) were applied as foliar sprays. Nep1 did not cause necrosis when applied with a nonionic surfactant or organosilicone surfactant plus unrefined corn oil. Plant age, protein concentration, organosilicone surfactant concentration, and the presence of a dew period influenced the amount of necrosis caused by Nep1. The addition of an 18-h dew period after treatment resulted in an increase of 10% or more in foliar necrosis at the 0.313 and 1.25 µg ml−1 (0.40 and 1.62 g ai ha−1) Nep1 concentrations. Increasing the spray volume from 129 ml m−2 (1,291.3 L ha−1) to 516 ml m−2 (5,165.2 L ha−1) more than doubled the amount of foliar necrosis caused by the 0.313 µg ml−1 (0.40 g ai ha−1 vs. 1.62 g ai ha−1) Nep1 concentration. A maximum necrosis rating of 95% was reached by 1.25 µg ml−1 Nep1 applied at 516 ml m−2 (6.46 g ai ha−1) followed by an 18-h dew period. Nep1 (6.46 g ai ha−1) remained active when coapplied to Centaurea maculosa with the herbicides 2,4-D or glyphosate (0.13 to 2.58 kg ai ha−1), causing foliar necrosis prior to the herbicides killing Centaurea maculosa. An increase in the organosilicone surfactant concentration from 1 to 2 ml ai L−1 was required to achieve levels of Nep1-induced necrosis on Centaurea maculosa acclimated to direct sun comparable to levels achieved on greenhouse-grown plants. Repeated application of Nep1 (6.48 g ai ha−1) 3 wk after an initial treatment (6.48 g ai ha−1) prevented the recovery of acclimated Centaurea maculosa. Greater damage was caused to acclimated Centaurea maculosa when Nep1 was applied near the middle of the day (80% necrosis at 10:00 A.M. and 85% necrosis at 2:00 P.M.) compared to early or late in the day (25% necrosis at 6:00 A.M. and 10% necrosis at 6:00 P.M.).

Type
Research Article
Copyright
Copyright © Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Ahrens, W. H. 1994. Herbicide Handbook, 7th ed. Champaign, IL: Weed Science Society of America, pp. 7781, 145–152.Google Scholar
Anonymous. 1970. Selected Weeds of the United States. Washington, DC: U.S. Department of Agriculture, Agricultural Research Service Agricultural Handbook 366, pp. 382383.Google Scholar
Bailey, B. A. 1995. Purification of a protein from culture filtrates of Fusarium oxysporum that induces ethylene and necrosis in leaves of Erythroxylum coca . Phytopathology 85:12501255.CrossRefGoogle Scholar
Bailey, B. A., Dean, J.F.D., and Anderson, J. D. 1990. An ethylene biosynthesis-inducing endoxylanase elicits electrolyte leakage and necrosis in Nicotiana tabacum cv Xanthi plants. Plant Physiol. 94:18491854.CrossRefGoogle Scholar
Bailey, B. A., Jennings, J. C., and Anderson, J. D. 1997. The 24-kDa protein from Fusarium oxysporum f.sp. erythroxyli: occurrence in related fungi and the effect of growth medium on its production. Can. J. Microbiol. 43:4555.CrossRefGoogle ScholarPubMed
Bailey, B. A., Korcak, R. F., and Anderson, J. D. 1992. Alterations in Nicotiana tabacum L. cv. Xanthi cell membrane function following treatment with an ethylene biosynthesis-inducing endoxylanase. Plant Physiol. 100:749755.Google ScholarPubMed
Baker, C. J., O’Neill, N. R., Keppler, L. D., and Orlandi, E. W. 1991. Early responses during plant-bacterial interactions in tobacco cell-suspensions. Phytopathology 81:15051507.CrossRefGoogle Scholar
Baker, C. J., Orlandi, E. W., and Mock, N. M. 1993. Harpin, an elicitor of the hypersensitive response in tobacco caused by Erwinia amylovora, elicits active oxygen production in suspension cells. Plant Physiol. 102:13411344.CrossRefGoogle ScholarPubMed
Christy, A. L., Herbst, K. A., Kostka, S. J., Mullen, J. P., and Carlson, P. S. 1993. Synergizing Weed Biocontrol Agents with Chemical Herbicides. Washington, DC: American Chemical Society, ACS Symposium Series 524. pp 87–100.CrossRefGoogle Scholar
Cole, D. J. 1985. Mode of action of glyphosate—a literature analysis. Pages 4874 In Grossbard, E. and Atkinson, D., eds. The Herbicide Glyphosate. London: Butterworths.Google Scholar
Devine, M. D., Duke, S. O., and Fedtke, C. 1993. Physiology of Herbicide Action. Englewood Cliffs, NJ: P.T.R. Pretice-Hall, pp. 252263, 298–301.Google Scholar
Jennings, J. C., Birkhold, P. C., Bailey, B. A., and Anderson, J. D. 2000. Induction of ethylene biosynthesis and necrosis in weed leaves by a Fusarium oxysporum protein. Weed Science 48:714.CrossRefGoogle Scholar
Jennings, J. C., Birkhold, P. C., Baker, C. J., Bailey, B. A., and Anderson, J. D. 1997. Physiological responses of tobacco to the 24 kDa elicitor from Fusarium oxysporum . Plant Physiol. 114 (Suppl.): 1454.Google Scholar
Ricci, P., Panabieres, F., Bonnet, P., et al. 1993. Proteinaceous elicitors of plant defense responses. Pages 121135. In Fritig, B. and Legrand, M., eds. Mechanisms of Plant Defense Responses. Dordrecht, The Netherlands: Kluwer Academic.CrossRefGoogle Scholar
Roberts, H. A. 1982. Weed Control Handbook: Principles. Oxford, Great Britain: British Crop Protection Council, Blackwell Scientific, pp 64–69.Google Scholar
Smith, E. A. and Oehme, W. 1992. The biological activity of glyphosate to plants and animals: a literature review. Vet. Hum. Toxicol. 34:531543.Google ScholarPubMed
Stevens, P.J.G. 1993. Organosilicone surfactants as adjuvants for agrochemicals. Pestic. Sci. 38:103122.CrossRefGoogle Scholar
Wei, Z.-M. and Beer, S. V. 1996. Harpin from Erwinia amylovora induces plant resistance. Acta Hortic. 411:223225.CrossRefGoogle Scholar