Phytotoxicity of methyl tert-butyl ether to common bean (Phaseolus vulgaris L.) plants.

The current investigation was conducted to report on the phytotoxicity of methyl tert-butyl ether (MTBE) to common bean (Phaseolus vulgaris L. cv. Nebraska) plants. The two-week-old potted plants were subjected to four weekly soil applications of aqueous MTBE concentrations (0, 1, 10, 25 and 50 ml L(-1)). The root growth, flower and pod development were more sensitive to MTBE treatments; while, stem growth and photosynthetic pigments were more persistent to the toxicity of MTBE. The total number of protein bands/lane in SDS-PAGE protein profile was reduced by MTBE treatments. Two proteins of molecular weight 53.83 and 30.96 kDa were newly synthesized at the highest concentrations (25 and 50 ml L(-1)) of MTBE; while the syntheses of other proteins were completely inhibited with varying sensitivity to MTBE concentrations. The toxicity of MTBE concentrations caused progressive collapsing of epidermal and cortical tissues of the plant roots. MTBE is quite toxic to crop plants in contaminated soils of agricultural systems.