Cycloheximide and buthionine sulfoximine prevent induction of genotoxic adaptation by cadmium salt against methyl mercuric chloride in embryonic shoot cells of Hordium vulgare L

Presoaked seeds of barley Hordeum vulgare L. pretreated with cycloheximide (CH), 10⁻⁶ M or bythionine sulfoximine (BSO), 10⁻⁴ M, were exposed to methyl mercuric chloride (MMCl), 10⁻⁴ M, with or without prior conditioning with cadmium sulfate (CdSO₄), 10⁻⁴ M. Subsequently as the seeds germinated the endpoints measured were mitotic index, cells with mitotic aberrations and micronuclei (MNC) in embryonic shoot cells fixed at 40, 44, 48 and 52 h of recovery. Indicated by the significance reduction (p ≤ 0.05) of the yield of cells with aberrations or MNC, the results confirmed that CdSO₄-conditioning triggered an adaptive response to MMCl-challenge. Pretreatments of CH and BSO, whereas they potentiated the genotoxicity of MMCl, significantly prevented (p ≤ 0.05) the Cd-induced genotoxic adaptation. That underscores a possible involvement of proteins in addition to phytochelatins in the underlaying mechanisms.