At all lead concentrations, the concentrations of K (the major
ion) in wheat and spinach are noticeably lower compared
to corresponding control values, and this decrease is already
observed with low lead concentrations. For 15 mM Pb, the
reduction of K concentrations (Table 2) is much lower in spinach
(38%) than in wheat (63%). Of course, owing to
growth inhibition, the reduction in K amount per plant is even
more impressive, especially in wheat