Chloroacetamide inhibition of fatty acid synthesis

• Published in: Pesticide biochemistry and physiology Vol. 32; no. 3; pp. 212 - 216
• Main Authors: Weisshaar, Hans, Retzlaff, G., Böger, Peter
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.11.1988; Elsevier
• Subjects: ACIDE GRAS; ACIDOS GRASOS; ALACHLOR; ALGAE; ALGUE; Biological and medical sciences; BIOSINTESIS; BIOSYNTHESE; BIOSYNTHESIS; Chemical control; ENSAYO; FATTY ACIDS; Freshwater; Fundamental and applied biological sciences. Psychology; HERBICIDAS; HERBICIDE; HERBICIDES; METAZACHLOR; Parasitic plants. Weeds; Phytopathology. Animal pests. Plant and forest protection; SCENEDESMUS; Scenedesmus acutus; TESTAGE; TESTING; Weeds; Alachlor; Algae; Chlorophycophyta; Biological model; Scenedesmus; Organic amide; Biosynthesis; Microorganism; Mechanism of action; Fatty acids; Herbicide; Thallophyta
• ISSN: 0048-3575; 1095-9939
• DOI: 10.1016/0048-3575(88)90103-4

The influence of alachlor and metazachlor on fatty acid synthesis of the green alga Scenedesmus acutus has been investigated. Autotrophic growth for 40 hr in the presence of 5 μ M alachlor or metazachlor led to a strong decrease in linolenic acid (18:3) content, while an increase in the palmitic (16:0) and oleic acid (18:1) content was observed. Furthermore, short-term incorporation studies (3 hr) with [2- 14C]acetate as the precursor of fatty acids showed a substantial inhibition of acetate incorporation into the fatty acid extract. Using TLC and HPLC techniques this extract exhibited one 14C-labeled fraction. As analyzed by gas chromatography linolenic acid is the main component in this fraction (more than 30%). A 5-μ M and 10-μ M sethoxydim application had no effect on acetate uptake with Scenedesmus. A combination of either metazachlor or alachlor with sethoxydim markedly improved the inhibitory activity of the chloroacetamides on acetate uptake. Our data suggest an inhibition of fatty acid biosynthesis between the C-elongation step of palmitic acid and the desaturation of oleic acid yielding linolenic acid.