Cd2+ fluxes from one-week-old Arabidopsis seedlings cultivated on 1/2 MS were detected. Net fluxes of Cd2+ in root hair were measured by the noninvasive micro-test technique (NMT; BIO-001A, Younger United States Science and Technology Corp, Beijing, China) combined with IFLUXES/IMFLUXES 2.0 software (NMT100 Series, Younger USA, Amherst, MA, USA) (Ma et al., 2015 (link)). The microelectrodes were calibrated in 0.1 and 0.01 mM Cd2+ before the measurements of Cd2+ flux. The electrodes with Nernstian slopes were > 29 ± 3 mv/decade. Arabidopsis seedlings were transferred into a measuring chamber containing 10 mL of measuring solution (0.1 mM KCl, 0.03 mM CdCl2, and 0.3 mM MES, pH 5.8.) and equilibrated for 10 min before measurement.
Visualization of free Cd2+ in Arabidopsis roots was conducted in one-week-old seedlings. The Cd probe Leadmium™ Green AM dye (Molecular Probes, Invitrogen, Calsbad, CA, USA) was utilized to detect the distribution of Cd in plant roots pre-treated with 150 μM Cd2+ for 0, 6 and 12 h. Cd fluorescence was excited at 488 nm and visualized using Zeiss LSM 780 (Carl Zeiss, Germany).
Visualization of free Cd2+ in Arabidopsis roots was conducted in one-week-old seedlings. The Cd probe Leadmium™ Green AM dye (Molecular Probes, Invitrogen, Calsbad, CA, USA) was utilized to detect the distribution of Cd in plant roots pre-treated with 150 μM Cd2+ for 0, 6 and 12 h. Cd fluorescence was excited at 488 nm and visualized using Zeiss LSM 780 (Carl Zeiss, Germany).