Abstract
The mode of action of the herbicide 3,7-dichloroquinolinecar-boxylic acid (quinclorac) was examined by measuring incorporation of [14C]glucose, [14C]acetate, [3H]thymidine, and [3H]uridine into maize (Zea mays) root cell walls, fatty acids, DNA, and RNA, respectively. Among the precursors examined, 10 [mu]M quinclorac inhibited [14C]glucose incorporation into the cell wall within 3 h. Fatty acid and DNA biosynthesis were subsequently inhibited, whereas RNA biosynthesis was unaffected. In contrast to the cellulose synthesis inhibitor 2,6-dichlorobenzonitrile, quinclorac strongly inhibited cellulose and a hemicellulose fraction presumed to be glucuronoarabinoxylan. However, the synthesis of (1->3),(1->4)-[beta]-D-glucans was only slightly inhibited. The degree of inhibition was time- and dose-dependent. By 4 h after treatment, the concentration that inhibited [14C]glucose incorporation into the cell wall, cellulose, and the sensitive hemicellulose fraction by 50% was about 15, 5, and 20 [mu]M, respectively. Concomitant with an inhibition of [14C]glucose incorporation into the cell wall, quinclorac treatment led to a marked accumulation of radioactivity in the cytosol. The increased radioactivity was found mostly in glucose and fructose. However, total levels of glucose, fructose, and uridine diphosphate-glucose were not changed greatly by quinclorac. These data suggest that quinclorac acts primarily as a cell-wall biosynthesis inhibitor in a susceptible grass by a mechanism that is different from that of 2,6-dichlorobenzonitrile.
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- Edelmann H. G., Fry S. C. Effect of cellulose synthesis inhibition on growth and the integration of xyloglucan into pea internode cell walls. Plant Physiol. 1992 Oct;100(2):993–997. doi: 10.1104/pp.100.2.993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gibeaut D. M., Carpita N. C. Tracing cell wall biogenesis in intact cells and plants : selective turnover and alteration of soluble and cell wall polysaccharides in grasses. Plant Physiol. 1991 Oct;97(2):551–561. doi: 10.1104/pp.97.2.551. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hall J. C., Bassi P. K., Spencer M. S., Vanden Born W. H. An evaluation of the role of ethylene in herbicidal injury induced by picloram or clopyralid in rapeseed and sunflower plants. Plant Physiol. 1985 Sep;79(1):18–23. doi: 10.1104/pp.79.1.18. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heim D. R., Skomp J. R., Tschabold E. E., Larrinua I. M. Isoxaben Inhibits the Synthesis of Acid Insoluble Cell Wall Materials In Arabidopsis thaliana. Plant Physiol. 1990 Jun;93(2):695–700. doi: 10.1104/pp.93.2.695. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Okuda K., Li L., Kudlicka K., Kuga S., Brown R. M., Jr [beta]-Glucan Synthesis in the Cotton Fiber (I. Identification of [beta]-1,4- and [beta]-1,3-Glucans Synthesized in Vitro). Plant Physiol. 1993 Apr;101(4):1131–1142. doi: 10.1104/pp.101.4.1131. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tittle F. L., Goudey J. S., Spencer M. S. Effect of 2,4-Dichlorophenoxyacetic Acid on Endogenous Cyanide, beta-Cyanoalanine Synthase Activity, and Ethylene Evolution in Seedlings of Soybean and Barley. Plant Physiol. 1990 Nov;94(3):1143–1148. doi: 10.1104/pp.94.3.1143. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yu Y. B., Yang S. F. Auxin-induced Ethylene Production and Its Inhibition by Aminoethyoxyvinylglycine and Cobalt Ion. Plant Physiol. 1979 Dec;64(6):1074–1077. doi: 10.1104/pp.64.6.1074. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhang G. F., Staehelin L. A. Functional compartmentation of the Golgi apparatus of plant cells : immunocytochemical analysis of high-pressure frozen- and freeze-substituted sycamore maple suspension culture cells. Plant Physiol. 1992 Jul;99(3):1070–1083. doi: 10.1104/pp.99.3.1070. [DOI] [PMC free article] [PubMed] [Google Scholar]