Cycloheximide and buthionine sulfoximine prevent induction of genotoxic adaptation by cadmium salt against methyl mercuric chloride in embryonic shoot cells of Hordum 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 significant reduction (p < or = 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 < or = 0.05) the Cd-induced genotoxic adaptation. That underscores a possible involvement of proteins in addition to phytochelatins in the underlaying mechanisms.