Figure 4: Relationship between shoot Ni2+ concentration and total chlorophyll concentration in M. crystallinum and B. juncea exposed for 3 months to increasing NiCl2 concentrations in the nutrient solution. Means (n = 6 per treatment ± SE) followed by the same letters are not significantly different at P ≤ 0.05. Bars marked with same letter are not significantly different at p= 0.05.