Hostname: page-component-77c89778f8-m42fx Total loading time: 0 Render date: 2024-07-17T18:49:27.187Z Has data issue: false hasContentIssue false

Germination Stimulants of Witchweed (Striga asiatica) from Hydrophobic Root Exudate of Sorghum (Sorghum bicolor)

Published online by Cambridge University Press:  12 June 2017

David H. Netzly
Affiliation:
Biochemistry Dep., Purdue Univ., West Lafayette, IN 47907
James L. Riopel
Affiliation:
Biol. Dep., Univ. Virginia, Charlottesville, VA 22901
Gebisa Ejeta
Affiliation:
Biochemistry Dep., Purdue Univ., West Lafayette, IN 47907
Larry G. Butler
Affiliation:
Biochemistry Dep., Purdue Univ., West Lafayette, IN 47907

Abstract

Hydrophobic exudate from roots of sorghum [Sorghum bicolor (L.) Moench. #3 SORVU ‘IS 8768’] contain four p-benzoquinones which in the dihydroquinone form are active as germination stimulants of witchweed [Striga asiatica (L.) Kuntz. # STRLU]. The three minor p-benzoquinones were partially characterized and found to be structurally similar to sorgoleone, the major p-benzoquinone of this exudate. Herbicidal activity of the hydrophobic exudate was due to concentration- and pH-dependent inhibition of root elongation in some but not all weeds tested. Witchweed has apparently adapted these “defense” compounds of sorghum as host-specific germination stimulants.

Type
Physiology, Chemistry, and Biochemistry
Copyright
Copyright © 1988 by the 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

1. Brown, R., Johnson, A. W., Robinson, E., and Todd, A. R. 1949. The stimulant involved in the germination of Striga hermonthica . Proc. R. Soc. B 136:112.Google Scholar
2. Brown, R., Johnson, A. W., Robinson, E., and Tyler, G. J. 1952. The Striga germination factor. 2. Chromatographic purification of crude concentrates. Biochem. J. 50:596600.Google Scholar
3. Chang, M. and Lynn, D. G. 1986. Haustoria and the chemistry of host recognition of parasitic angiosperms. J. Chem. Ecol. 12:561579.Google Scholar
4. Chang, M., Netzly, D. H., Butler, L. G., and Lynn, D. G. 1986. Chemical regulation of distance: Characterization of the first natural host germination stimulant for Striga asiatica . J. Am. Chem. Soc. 108:78587860.Google Scholar
5. Cook, C. E., Whichard, L. P., Wall, M. E., Egley, G. H., Coggon, P., Luhan, P. A., and McPhail, A. T. 1972. Germination stimulants. II. The structure of Strigol – a potent seed germination stimulant for witchweed (Striga lutea Lour.). J. Am. Chem. Soc. 94:61986199.Google Scholar
6. Egley, G. H. and Dale, J. E. 1970. Ethylene, 2-chloroethyl phosphonic acid, and witchweed germination. Weed Sci. 18:586589.Google Scholar
7. Johnson, A. W., Roseberry, G., and Parker, C. 1976. A novel approach to Striga and Orobanche control using synthetic germination stimulants. Weed Res. 16:223227.Google Scholar
8. Musselman, L. J. 1980. The biology of Striga, Orobanche, and other root-parasitic weeds. Annu. Rev. Phytopathol. 18:463489.CrossRefGoogle Scholar
9. Netzly, D. H. and Butler, L. G. 1986. Roots of Sorghum bicolor exude hydrophobic droplets that contain biologically active materials. Crop Sci. 26:775778.Google Scholar
10. Netzly, D. H., Ejeta, G., Housley, T., Hess, D., and Butler, L. 1986. Mechanisms of resistance to Striga in sorghum. Page 5051 in Proceedings of a Workshop on Biology and Control of Orobanche. LH/VPT, Wageningen, The Netherlands.Google Scholar
11. Nickrent, D. L., Musselman, L. J., Riopel, J. L., and Eplee, R. E. 1979. Haustorial initiation and non-host penetration in witchweed (Striga asiatica). Ann. Bot. 43:233236.Google Scholar
12. Nour, J., Press, M., Stewart, G., and Tuohy, J. 1986. Africa in the grip of witchweed. New Sci. 109:4448.Google Scholar
13. Pesch, C., Pieterse, A. H., and Stoop, W. A. 1983. Inhibition of germination in Striga by means of urea. Page 3738 in Proceedings of the Second International Workshop on Striga. ICRISAT. Ouagadougou, Upper Volta.Google Scholar
14. Riopel, J. L. and Baird, W. V. 1987. Morphogenesis of the early development of primary haustoria in Striga asisatica . Pages 107125 in Musselman, L. J., ed. Parasitic Weeds in Agriculture. Vol. I. Striga. CRC Press, Boca Raton, FL.Google Scholar
15. Riopel, J. L. and Musselman, L. J. 1979. Experimental initiation of haustoria in Agalinis purpurea . Am. J. Bot. 66:570575.Google Scholar
16. Steffens, J. C., Lynn, D. G., Kamat, V. S., and Riopel, J. L. 1982. Molecular specificity of haustorial induction in Agalinis purpurea (L.) Raf. (Scrophlariaceae) Ann. Bot. 50:17.Google Scholar
17. Sunderland, N. 1960. The production of the Striga and robanche germination stimulants by maize roots. I. The number and variety of stimulants. J. Exp. Bot. 11:236245.CrossRefGoogle Scholar
18. Symes, W. F. and Dawson, C. R. 1954. Poison ivy “urushiol”. J. Am. Chem. Soc. 76:29592963.Google Scholar
19. Van Staden, J. 1976. The release of cytokinins by maize roots. Plant Sci. Lett. 7:279283.Google Scholar
20. Worsham, A. D. 1987. Germination of witchweed seeds. Pages 4561 in Musselman, L. J., ed. Parasitic weeds in Agriculture. Vol. I. Striga. CRC Press, Boca Raton, FL.Google Scholar