The effect of sublethal concentrations of crude oil on the growth and metabolism of cowpea (Vigna unguiculata) seedlings

The effect of crude oil contaminated soil at various sublethal concentrations (0.25%, 0.5%, 1.0% and 2.0%) on the growth and metabolism of cowpea (Vigna unguiculata) seedlings was studied. The results showed that crude oil induced environmental stress in the seedlings. This is indicated by the increase in free sugar, total protein and amino acids and a decrease in chlorophyll contents of the leaves of 12-day-old seedlings. The activities of total amylase and starch phosphorylase from the cotyledon and mitotic activity of the meristems of the root of 4-day-old seedling were inhibited by the various concentrations except at 0.5%, which showed stimulation of cellular and metabolic activities relative to seedlings in the control treatment. © 2006 Springer Science + Business Media, Inc.