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Structure Versus Activity of Substituted Pyridazinones as Related to Mechanism of Action

Published online by Cambridge University Press:  12 June 2017

J. B. St. John  and
J. L. Hilton
J. B. St. John
Affiliation:
Plant Physiol., Agr. Res. Serv., U.S. Dep. Agric., Beltsville, MD 20705
J. L. Hilton
Affiliation:
Plant Physiol., Agr. Res. Serv., U.S. Dep. Agric., Beltsville, MD 20705
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Abstract

In at least three metabolic processes in wheat (Triticum aestivum L. var. ‘Arthur’) shoots inhibitory activity can be related to the chemical structure of substituted pyridazinones. Inhibitory activities include: inhibition of the Hill reaction and photosynthetic CO2 fixation; inhibition of carotenoid biosynthesis accompanied by photodestruction of chlorophyll; and interference with the formation of chloroplast membrane polar lipids. The parent compound, pyrazon [5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone], inhibits the Hill reaction and photosynthetic CO2 fixation. Trifluoromethyl substitution of the phenyl ring of pyrazon, mono-methyl substitution of the amine, or substitutions at both positions result in inhibition of carotenoid biosynthesis. However, both substitutions are required for maximum effect. Substitutions onto the molecular structure of pyrazon are also related to alterations in the formation of membrane polar lipids. Dimethyl substitution of the amine of pyrazon is related to a decrease in linolenic acid accompanied by an increase in linoleic acid without a shift in the relative proportion of saturated to unsaturated fatty acids of the membrane lipids. The trifluoromethyl substitution of the phenyl ring and mono-methyl substitution of the amine are related to a shift toward a higher proportion of saturated fatty acids of chloroplast membrane lipids. Results obtained with diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] and with dark-grown wheat tissue indicated that activity of the pyridazinones on the formation of membrane lipids was probably not related to inhibition of the Hill reaction.

Type
Research Article
Information
Weed Science , Volume 24 , Issue 6 , November 1976 , pp. 579 - 582
Copyright
Copyright © 1977 by the Weed Science Society of America 

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References

Literature Cited

1. Arnon, D.I. 1949. Copper enzymes of isolated chloroplasts: Polyphenoloxidase in Beta vulgaris . Plant Physiol. 24:1–15.CrossRefGoogle ScholarPubMed
2. Bartels, P.G. and Hyde, A. 1970. Chloroplast development in 4-chloro-5-(dimethylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone (Sandoz 6706)-treated wheat seedlings. Plant Physiol. 45:807–810.CrossRefGoogle Scholar
3. Bartels, P.G. and McCullough, C. 1972. A new inhibitor of carotenoid synthesis in higher plants: 4-chloro-5-(dimethylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone (Sandoz 6706). Biochem. Biophys. Res. Commun. 48:16–22.CrossRefGoogle Scholar
4. Ben-Aziz, A. and Koren, E. 1974. Interference in carotenogenesis as a mechanism of action of the pyridazinone herbicide Sandoz 6706. Accumulation of C-40 carotenoid precursors, inhibition of β-carotene synthesis and enhancement of phytoene epoxidation. Plant Physiol. 54:916–920.CrossRefGoogle ScholarPubMed
5. Böttcher, C.J., Woodford, F.P., Boelama-Van Haute, E., and Gent, C.M. 1959. Methods for the analysis of lipids extracted from human arteries and other tissues. Rec. Trav. Chim. 78:794–814.CrossRefGoogle Scholar
6. Britton, G. and Goodwin, T.W. 1971. Biosynthesis of carotenoids. Methods Enzymol. 8:654–701.CrossRefGoogle Scholar
7. Burchfield, H.P. and Storrs, E.E. 1962. Biochemical Applications of Gas Chromatography. Academic Press, New York. 680 pp.Google Scholar
8. Davies, B.H. 1965. Analysis of carotenoid pigments. Pages 489–532 in Godwin, T.W., ed., Chemistry and Biochemistry of Plant Pigments. Academic Press, London.Google Scholar
9. Devlin, R.M. and Karczmarczyk, S.J. 1975. Influence of norflurazon on chlorophyll production. Proc. Northeastern Weed Sci. Soc. 29:161–167.Google Scholar
10. Folch, J., Lees, M., and Stanley, G.H. 1957. A simple method for the isolation and purification of total lipids from animal tissue. J. Biol. Chem. 226:497–509.CrossRefGoogle Scholar
11. Hilton, J.L., Scharen, A.L., St. John, J.B., Moreland, D.E., and Norris, K.H. 1969. Modes of action of pyridazinone herbicides. Weed Sci. 17:541–547.CrossRefGoogle Scholar
12. Hilton, J.L., St. John, J.B., Christiansen, M.N., and Norris, K.H. 1971. Interaction of lipoidal materials and a pyridazinone inhibitor of chloroplast development. Plant Physiol. 48:171–177.CrossRefGoogle Scholar
13. Metcalfe, L.D. and Schmitz, A.A. 1961. The rapid preparation of fatty acid esters for gas chromatographic analysis. Anal. Chem. 33:363–364.CrossRefGoogle Scholar
14. Nichols, B.W. and James, A.T. 1968. The function and metabolism of fatty acids and acyl lipids in chloroplasts. Pages 163–178 in Pridman, J.B., ed., Plant Cell Organelles, Proceedings of the Phytochemistry Group Symposium. Academic Press, London.Google Scholar
15. Strang, R.H. and Rogers, R.L. 1974. Behavior and fate of two phenyl pridazinone herbicides in cotton, corn, and soybean. J. Agric. Food Chem. 22:1119–1125.CrossRefGoogle Scholar
16. St. John, J.B. and Hilton, J.L. 1973. Lipid metabolism as a site of herbicide action. Weed Sci. 21:477–479.CrossRefGoogle Scholar
17. St. John, J.B. and Christiansen, M.N. 1976. Inhibition of linolenic acid synthesis and modification of chilling resistance in cotton seedlings. Plant Physiol. 57:257–259.CrossRefGoogle Scholar
18. Sumida, S. and Ueda, M. 1973. Studies of pesticide effects on Chlorella metabolism I. Effect of herbicides on complex lipid biosynthesis. Plant Cell Physiol. 14:781–785.Google Scholar
19. Sumida, S., Yoshida, R., and Ueda, M. 1975. Studies of pesticide effects on Chlorella metabolism II. Effect of DCMU on galactolipid metabolism. Plant Cell Physiol. 16:257–264.Google Scholar