Novel potato plants with enhanced cadmium resistance and antioxidative defence generated after in vitro cell line selection

It is of interest to apply plant tissue culture to generate plants resistant to toxic effects of cadmium (Cd) on plant growth. Callus cultures were initiated from leaf explants of micropropagated potato plantlets (Solanum tuberosum L., cv. Iwa) for in vitro selection comprising 18 different Cd treatments varying in Cd exposure timing and duration. Plantlets regenerated from two different lines of Cd-selected calli, L9 and L11, were found to exhibit enhanced resistance to 218 μM Cd compared to control (source plantlets for leaf explants used to initiate callus cultures for Cd resistance). In response to 218 μM Cd, L11 plantlets had lower levels of lipid peroxidation and hydrogen peroxide than control and L9 plantlets. In addition, antioxidative enzyme activities in L11 were generally higher than control. L11 also had a higher level of proline than control.