The contents of free Asp and Asp-derived amino acids in leaves of 4-week-old plants. Asp (A), Lys (B), Met (C), Thr (D), Ile (E), and the total amount of Asp-derived amino acids Lys, Met, Thr, and Ile (F). Values are presented as means ± se (n = 5). Values not connected by the same letter are significantly different (Student’s t test, P < 0.05). Values connected by the same letter are not significantly different. FW, Fresh weight; Col WT, Col-0 wild type.