Cadmium-induced changes in growth and cell cycle gene expression in suspension-culture cells of soybean

The toxic effects of cadmium on growth and development of living organisms are well documented. However, the molecular mechanisms responsible for the inhibition of plant growth by cadmium are still not completely understood. We determined the effects of cadmium concentrations in the range of 1–11 μM on the growth of Glycine max L. cv. Navico suspension-culture cells, as well as on the expression of two cell cycle genes: cyclin B1 and cyclin-dependent type A kinase (CDK-A). There was no detectable decrease in cell viability at any tested Cd2+ concentrations. The lower concentrations of Cd2+ (1–4 μM) stimulated cell culture growth; however, this did not correspond with increased expression of cell cycle genes. The inhibition of cell growth was observed at concentration of Cd2+ higher than 6 μM. Interestingly, it correlated well with the decreased cyclin B1 mRNA levels, but had no significant effect on the levels of CDK-A mRNA.