Assessing the effects of accumulated Cd(II) on seed germination and root development of Arabidopsis thaliana

In this study, Arabidopsis thaliana was used as a model system to assess the toxic effects of cadmium on plant development and growth. The germination and growth of A. thaliana was inhibited by Cd(II), and the inhibitory effect was dosage-dependent. The significant decrease of germination rates and root growths of A. thaliana were observed from 50 mg/L and 25 mg/L of CdCl2, respectively. Although both shoot and root growths were suppressed by Cd(II), root developments were more sensitive to Cd(II) than shoot developments, as evidenced by shoot growths observed over 50 mg/L of CdCl2. In the concordance to this result, it was also observed that the expression of DR5::VENUS, a visual marker of auxin response, was dependent on the Cd(II) concentration and was strongly reduced from 5 mg/L of CdCl2. In addition, the E. coli-based biosensors were employed to quantify accumulated Cd(II) in plants to understand the correlation between toxic effects and Cd(II) in plants. As a result, it was revealed that 0.012 mg/g and 0.138 mg/g of Cd(II) in dried plants were corresponded to the concentration inhibiting root developments and root growths, respectively. Although it needs further investigations, the findings play a significant role in assessing the toxic effects of Cd(II) based on the relationship between the toxic effects and accumulated Cd(II) concentrations in plants.