Abstract
Effects of the herbicide safeners N,N-diallyl-2,2-dichloroacetamide and 4-dichloroacetyl-3,4-dihydro-3-methyl-2H-1,4-benzooxazin (CGA 154281) on the contents in cysteine and glutathione, on the assimilation of 35SO42−, and on the enzymes of assimilatory sulfate reduction were analyzed in roots and primary leaves of maize (Zea mays) seedlings. Both safeners induced an increase in cysteine and glutathione. In labeling experiments using 35SO42−, roots of plants cultivated in the presence of safeners contained an increased level of radioactivity in glutathione and cysteine as compared with controls. A significant increase in uptake of sulfate was only detected in the presence of CGA 154281. One millimolar N,N-diallyl-2,2-dichloroacetamide applied to the roots for 6 days increased the activity of adenosine 5′-phosphosulfate sulfotransferase about 20- and threefold in the roots and leaves, respectively, compared with controls. CGA 154281 at 10 micromolar caused a sevenfold increase of this enzyme activity in the roots, but did not affect it significantly in the leaves. A significant increase in ATP-sulfurylase (EC 2.7.7.4) activity was only detected in the roots cultivated in the presence of 10 micromolar CGA 154281. Both safeners had no effect on the activity of sulfite reductase (EC 1.8.7.1) and O-acetyl-l-serine sulfhydrylase (EC 4.2.99.8). The herbicide metolachlor alone or combined with the safeners induced levels of adenosine 5′-phosphosulfate sulfotransferase, which were higher than those of the appropriate controls. Taken together these results show that the herbicide safeners increased both the level of adenosine 5′-phosphosulfate sulfotransferase activity and of the thiols cysteine and glutathione. This indicates that these safeners may be involved in eliminating the previously proposed regulatory mechanism, in which increased concentrations of thiols regulate assimilatory sulfate reduction by decreasing the activities of the enzymes involved.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
- Brunold C. Regulation of Sulfate Assimilation in Plants: 7. Cysteine Inactivation of Adenosine 5'-Phosphosulfate Sulfotransferase in Lemna minor L. Plant Physiol. 1978 Mar;61(3):342–347. doi: 10.1104/pp.61.3.342. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nussbaum S., Schmutz D., Brunold C. Regulation of Assimilatory Sulfate Reduction by Cadmium in Zea mays L. Plant Physiol. 1988 Dec;88(4):1407–1410. doi: 10.1104/pp.88.4.1407. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Reuveny Z., Filner P. Regulation of adenosine triphosphate sulfurylase in cultured tobacco cells. Effects of sulfur and nitrogen sources on the formation and decay of the enzyme. J Biol Chem. 1977 Mar 25;252(6):1858–1864. [PubMed] [Google Scholar]
- Richie J. P., Jr, Lang C. A. The determination of glutathione, cyst(e)ine, and other thiols and disulfides in biological samples using high-performance liquid chromatography with dual electrochemical detection. Anal Biochem. 1987 May 15;163(1):9–15. doi: 10.1016/0003-2697(87)90085-6. [DOI] [PubMed] [Google Scholar]
- Rüegsegger A., Schmutz D., Brunold C. Regulation of Glutathione Synthesis by Cadmium in Pisum sativum L. Plant Physiol. 1990 Aug;93(4):1579–1584. doi: 10.1104/pp.93.4.1579. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schiff J. A., Levinthal M. Studies of sulfate utilization by algae. 4. Properties of a cell-free sulfate-reducing system from chlorella. Plant Physiol. 1968 Apr;43(4):547–554. doi: 10.1104/pp.43.4.547. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schmutz D., Brunold C. Rapid and simple measurement of ATP-sulfurylase activity in crude plant extracts using an ATP meter for bioluminescence determination. Anal Biochem. 1982 Mar 15;121(1):151–155. doi: 10.1016/0003-2697(82)90569-3. [DOI] [PubMed] [Google Scholar]
- Tsang M. L., Lemieux J., Schiff J. A., Bojarski T. B. Preparation of adenosine 5'-phosphosulfate (APS) from adenosine 3'-phosphate 5'-phosphosulfate (PAPS) prepared by an improved procedure. Anal Biochem. 1976 Aug;74(2):623–626. doi: 10.1016/0003-2697(76)90249-9. [DOI] [PubMed] [Google Scholar]