Hostname: page-component-848d4c4894-8kt4b Total loading time: 0 Render date: 2024-07-06T19:52:16.075Z Has data issue: false hasContentIssue false

Thidiazuron stimulates germination and ethylene production in Striga hermonthica – comparison with the effects of GR-24, ethylene and 1-aminocyclopropane-1-carboxylic acid

Published online by Cambridge University Press:  19 September 2008

David C. Logan*
Affiliation:
Striga Research Group, Department of Biology, University College London, Gower Street, London WC1E 6BT, UK
George R. Stewart
Affiliation:
Striga Research Group, Department of Biology, University College London, Gower Street, London WC1E 6BT, UK
*
*correspondence

Abstract

Seed germination of the hemiparasitic angiosperm Striga hermonthica is elicited by compounds present in the root exudates of the host plant. A variety of chemicals can substitute for the host-derived signal although the exact mechanism through which these act is unknown. In the present study, thidiazuron (TDZ), a cytokinin-active urea derivative was found to stimulate germination. This thidiazuron-induced germination was shown to be mediated by endogenous ethylene, by a similar mechanism to germination induced by host-root exudate and the synthetic stimulant GR-24. Comparing the effects of TDZ, host-root exudate, GR-24 and the ethylene precursor 1-aminocyclopropane-1-car-boxylic (ACC) suggests that ethylene production increases as a result of increased ACC synthesis and is consistent with a model for Striga seed germination in which host-derived signals and other stimulants act by eliciting the synthesis of ethylene via a stimulation of ACC synthase activity. All germination stimulants tested trigger a rapid increase in O2 uptake by conditioned seeds. The patterns of O2 uptake following TDZ or GR-24 treatments show similarities and three distinct phases of respiration are apparent. In contrast, stimulation of O2 uptake by ethylene results in a different pattern, with no distinct phases obvious following the initial burst of activity.

Type
Research Papers
Copyright
Copyright © Cambridge University Press 1995

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.)

Footnotes

1

Present address Laboratoire de Biochimie et Physiologie Végétales, INRA/ENSA-M/CNRS, URA-573, F-34060, Monpellier, France

2

Present address Department of Botany, The University of Queensland, St. Lucia, Brisbane, Queensland 4067, Australia

References

Adams, D.O. and Yang, S.F. (1979) Ethylene biosynthesis: identification of 1-aminocyclopropane-1-carboxylic acid as an intermediate in the conversion of methionine to ethylene. Proceedings of the National Academy of Sciences, USA 76, 170174.CrossRefGoogle Scholar
Abeles, F.B., Morgan, P.W. and Saltveit, M.K. (1992) Ethylene in plant biology. 2nd Edition. London, Academic Press.Google Scholar
Babiker, A.G.T., Butler, L.G., Ejeta, G. and Woodson, W.R. (1993a) Ethylene biosynthesis and strigol-induced germination of Striga asiatica. Physiologia Plantarum 88, 359365.CrossRefGoogle Scholar
Babiker, A.G.T., Butler, L.G., Ejeta, G. and Woodson, W.R. (1993b) Enhancement of ethylene biosynthesis and germination by cytokinins and 1-aminocyclopropane-1-carboxylic acid in Striga asiatica seeds. Physiologia Plantarum 89, 2126.CrossRefGoogle Scholar
Bewley, J.D. and Black, M. (1983) Physiology and germination of seeds in relation to germination I. Development, germination, and growth. Berlin, Heidelberg, New York, Springer-Verlag.Google Scholar
Igbinnosa, I. and Okonkwo, S.N.C. (1992) Stimulation of germination of seeds of cowpea witchweed (Striga gesnerioides) by sodium hypochlorite and some plant growth regulators. Weed Science 40, 2528.CrossRefGoogle Scholar
Jackson, M.B. and Parker, C. (1991) Induction of germination by strigol analogues requires ethylene action in Striga hermonthica but not in S. forbesii. Journal of Plant Physiology 138, 383386.CrossRefGoogle Scholar
Johnson, A.W., Rosebury, G. and Parker, C. (1976) A novel approach to Striga and Orobanche control using synthetic germination stimulants. Weed Research 16, 223227.CrossRefGoogle Scholar
Kang, B.G., Yocum, C.S., Burg, S.P. and Ray, P.M. (1967) Ethylene and carbon dioxide; mediation of hypocotyl hook-opening response. Science 156, 958959.CrossRefGoogle ScholarPubMed
Kende, H. (1989) Enzymes of ethylene biosynthesis. Plant Physiology 91, 14.CrossRefGoogle ScholarPubMed
Logan, D.C. and Stewart, G.R. (1991) Role of ethylene in the germination of the hemiparasite Striga hermonthica. Plant Physiology 97, 14351438.CrossRefGoogle ScholarPubMed
Logan, D.C. and Stewart, G.R. (1992) Germination of the seeds of parasitic angiosperms. Seed Science Research 2, 179190.CrossRefGoogle Scholar
McKeon, T.A., Hoffman, N.E. and Yang, S.F. (1982) Effect of plant hormone pretreatments on ethylene production and synthesis of 1-aminocyclopropane-1-carboxylic acid in water stressed wheat leaves. Planta 155, 437443.CrossRefGoogle Scholar
Mok, M.C., Mok, D.W.S., Armstrong, D.J., Shudo, K., Isoga, Y. and Okamoto, T. (1982) Cytokinin activity of N-phenyl-N'-1,2,3-thidiazol-5-ylurea (thidiazuron). Phytochemistry 21, 15091511.CrossRefGoogle Scholar
Raghavan, V. and Okonkwo, S.N.C. (1982) Studies on the germination of seeds of the root parasites Alectra vogeli and Striga gesnerioides. II. DNA synthesis and development of the quiescent centre in the radicle. American Journal of Botany 69, 16461656.CrossRefGoogle Scholar
Sisler, E.C. and Yang, S.F. (1984) Anti-ethylene effects of cis-2-butene and cyclic olefins. Phytochemistry 23, 27652768.CrossRefGoogle Scholar
Sokal, R.R. and Rohlf, F.J. (1981) Biometry. 2nd Edition. New York, W.H. Freeman and Company.Google Scholar
Suttle, J.C. (1984) Effect of the defoliant thidiazuron on ethylene evolution from mung bean hypocotyl segments. Plant Physiology 75, 902907.CrossRefGoogle ScholarPubMed
Suttle, J.C. (1986) Cytokinin-induced ethylene biosynthesis in nonsenescing cotton leaves. Plant Physiology 82, 930935.CrossRefGoogle ScholarPubMed
Worsham, A.D. (1987) Germination of witchweed seeds. pp 4561 in Musselman, L.J. (Ed.) Parasitic weeds in agriculture I. Striga. Florida, CRC Press.Google Scholar
Worsham, A.D., Moreland, D.E. and Klingman, G.C. (1959) Stimulation of Striga asiatica (witchweed) seed germination by 6-substituted purines. Science 130, 16541656.CrossRefGoogle Scholar
Yang, S.F. (1980) Regulation of ethylene biosynthesis. HortScience 15, 238243.CrossRefGoogle Scholar
Zwanenburg, B., Mhehe, G.L., 't Lam, G.K., Dommerholt, F.J. and Kishimba, M.A. (1986) The search for new germination stimulants of Striga pp 3541 inter Borg, S.J. (Ed.) Biology and control of Orobanche. Wageningen, Netherlands, LH/VPO.Google Scholar