Figure 1.

Sulfate (A), phosphate (B), and nitrate (C) concentrations (micromoles gram⁻¹ fresh weight [FW]) in shoots (white bars) and roots (gray bars) of tomato plants subjected to varying nutritional stress. Data are means ± sd of six independent replicates run in triplicate. Significant differences between samples are indicated by different letters: different uppercase letters indicate significant differences in roots (P < 0.05), and different lowercase letters indicate significant differences in shoots (P < 0.05). C, Control; D, dual deficiency; F, Fe deficiency; S, S deficiency.