Fig. 1.
Effect of N-form on growth of Micro-Tom tomato plants under Cd-free or Cd-exposed condition. (a) The root biomass. (b) The shoot biomass. The plants were pre-cultured in the growth solution contained both NO3− and NH4+ for 12 d and were then transferred to Cd-free or 2 μM Cd-added growth solutions with either NO3− or NH4+ as the sole nitrogen source. The pH in the all treatments was buffered at 5.5 using MES. The shoots and roots of plants after 8 d of treatments were harvested for biomass analysis. Data are means ±SD (n=4). * Significant differences (P < 0.05) between NO3− and NH4+ treatments.