Aluminum effects on lipid peroxidation and on the activities of enzymes of oxidative metabolism in sorghum.
Year: 1999
Type: article
Abstract: Seedlings of two sorghum (Sorghum bicolor (L.) Moench) cultivars with differential tolerance to Al were exposed to 0 and 185 µM of Al, in a pH 4.0 nutrient solution, for 10 days and, then, lipid peroxidation and the activity of enzymes of the oxidative metabolism were determined. Lipid peroxidation increased in the root system of the two cultivars, especially in the sensitive one. In the presence of Al, superoxide dismutase and cinnamyl alcohol dehydrogenase activities increased only in the Al-tolerant cultivar. In this cultivar the largest reduction in phenylalanine ammonia lyase activity also occurred. So, this cultivar probably accumulated less amounts of reactive oxygen species and of toxic phenolic compounds and, consequently, showed smaller lipid peroxidation. On the other hand, largest increases in peroxidase and polyphenoloxidase activities were observed in the Al-sensitive cultivar in the presence of Al. In this cultivar a greater accumulation of peroxides and phenolic compounds probably occurred resulting in more lipid peroxidation. The changes in ascorbate peroxidase and catalase activities in both cultivars suggest a reduced contribution of these enzymes in the mechanism of peroxide decomposition. The results indicate that the Al-tolerant cultivar produces smaller concentrations of reactive oxygen species and/or it possesses more efficient enzymatic mechanisms of removal and/or neutralization of these radicals than the Al-sensitive cultivar. Additional index terms: Al toxicity, free oxygen radicals, peroxides, Sorghum bicolor. EFEITOS DO ALUMINIO SOBRE A PEROXIDACAO DE LIPIDIOS E A ATIVIDADE DE ENZIMAS DO METABOLISMO OXIDATIVO EM SORGO
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W2463779135