Figure 5.

Effect of the addition of exogenous Suc on the response of the roots of NH₄⁺-fed plants to N limitation. The CNH₄⁺ and LNH₄⁺ roots of NH₄⁺-fed plants described in Figure 5 were supplied with 1% Suc during the N limitation treatment: general presentation of the split-root experiment (A); main sugars and organic acids relative content (B); net NH₄⁺ intake (C). The values are the means of six replicates. Vertical bars indicate sd. *A significant difference was found for all compounds between Suc treated and untreated organs according to t test (P < 0.001).