The decline in potassium concentration is associated with cadmium toxicity of rice seedlings

Cadmium (Cd) is one of the most dangerous environmental pollutants, among other things, affecting plant mineral composition. Thus, in this study, we investigated the changes in potassium (K) concentration in Cd-treated rice (Oryza sativa L.) seedlings of two cultivars. On treatment with 5 μM CdCl₂, the Cd concentration increased in the shoot and roots of Cd-sensitive cultivar (cv. Taichung Native 1, TN1) but not or slightly in the Cd-tolerant cultivar (cv. Tainung 67, TNG67). The decrease in K concentration in the shoot and roots of TN1 caused by Cd was more pronounced than that of TNG67. Exogenous addition of KCl decreased Cd concentration and reduced Cd toxicity of TN1 seedlings. Evidence presented in this study suggests that the improvement of K status is able to reduce toxicity of rice seedlings to CdCl₂.