Figure 4: Changes in Pb2+ concentration (μg g-1 DW) in shoots of S. portulacastrum and B. juncea grown for 21 days in various split-root system. B/B: whole root system in basal medium; Pb/Pb: whole root system in basal medium supplemented with 400 μM Pb(NO3)2; B-K; B-Ca and B-N: basal medium deprived of K+; Ca2+ or N, respectively. Means of eight replicates. Bars marked with same letter are not significantly different at P = 0.05.