Effect of cadmium on the phenolic compounds formation in the callus cultures derived from various organs of the tea plant

The effects of cadmium (6.3 × 10^?5 M or 10.6 × 10^?5 M) on the growth of tea plant (Camellia sinensis L.) callus cultures derived from leaves, stems, and roots and on the formation, in these cultures, of phenolic compounds, including flavans and lignin, which are characteristic of the tea plant, were investigated. In the calli derived from leaves and stems, cadmium treatment decreased the biomass increment, while in the calli derived from roots, growth characteristics remained at the control level. Under the effect of cadmium, the content of phenolic compounds, including flavans, in the leaf calli decreased, while in the stem and root calli, it either increased (at the cadmium concentration of 6.3 × 10^?5 M), or was close to a control one (at the cadmium concentration of 10.6 × 10^?5 M). The lignin content in the root and stem calli increased, but it did not change in the leaf calli. All this data demonstrate that the cadmium-induced changes in phenolic metabolism of the tea plant callus culture depended both on the cadmium concentration in the medium and on the origin of calli.