Fig. 1.

Effects of Pb²⁺ stress on net NO₃⁻ influx in the roots of Arabidopsis Col-0 plants. Seedlings at 4 d old were transferred to medium with or without 300 μM Pb(CH₃COO)₂ and net NO₃⁻ influx was measured after 3 d using a non-invasive microelectrode ion flux measurement system. Measurements were taken in the meristematic (A), elongation (B), and maturation zones (C) of the roots. Data are means (±SE) of six biological replicates. Significant differences were determined using two-tailed Student’s t-tests: *P<0.05. (This figure is available in colour at JXB online.)