Effects of the Herbicide Sethoxydim and the Safener Dichlormid on Lipid Synthesis and Acetyl-CoA Carboxylase Activity of Grain Sorghum*
نویسنده
چکیده
The effects o f individual or combined treatment o f the cyclohexanedione herbicide sethoxy dim and the safener dichlormid on total lipid synthesis, protein synthesis and acetyl-CoA car boxylase (ACCase, EC 6.4.1.12) activity o f grain sorghum [Sorghum bicolor (L.) M oench, var. G623] were investigated. Sethoxydim and dichlormid were tested at concentrations o f 0, 5, 50, and 100 |iM each. Sethoxydim applied alone at 50 and 100 ( im , inhibited the incorporation o f [l4C]acetate into total lipids o f sorghum leaf protoplasts by more than 50%, following a 4 h incubation. Dichlormid antagonized partially the inhibitory effects o f sethoxydim on the in corporation o f acetate into total lipids o f sorghum protoplasts only when it was used at 100 |iM . Sethoxydim applied alone inhibited the incorporation o f [l4C]leucine into sorghum leaf protoplasts only at 100 ^m. Dichlormid was not inhibitory o f this process at any concen tration. The combined effects o f sethoxydim and dichlormid on this process were mainly addi tive indicating no interactions o f the two chemicals. Sethoxydim applied alone at 5 and 50 (iM inhibited the activity o f ACCase extracted from leaf tissues o f grain sorghum seedlings by 58 and 90%, respectively. Addition o f the safener dichlormid to the assay medium did not inhibit ACCase activity o f sorghum leaves even at the high concentration o f 50 |iM . The combined effects o f sethoxydim and dichlormid on the activity o f sorghum ACCase were similar to those observed when sethoxydim was used alone. These results indicate that the protection con ferred by dichlormid on grain sorghum against sethoxydim injury can not be explained on the basis o f an antagonistic interaction o f the two chemicals on target metabolic processes (lipid synthesis) or target enzymes (ACCase).
منابع مشابه
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