Figure 9.

Effects of elevated CO₂ on wild-type (WT; white bars), dfc (black bars), and DFC complementation (gray bars) seedlings on 0.3 or 9.4 n medium. A, The primary root length of seedlings under N-limited conditions with ambient air or elevated CO₂. B, Wild-type, dfc, and DFC complementation seedlings grown on the 0.3 n medium for 9 d with elevated CO₂. C, Total free amino acid contents of 12-d-old seedlings on 0.3 or 9.4 n medium with elevated CO₂. D, Contents of some individual amino acids in 12-d-old seedlings on the 9.4 n medium with elevated CO₂. E, Contents of some individual amino acids in 12-d-old seedlings on the 0.3 n medium with elevated CO₂. F, The percentage of each folate in the sum of the amount of folylpolyglutamates (5-M-THF-Glu_n and 5-F-THF-Glu_n; n = 1–4) in 12-d-old seedlings on 0.3 or 9.4 n medium with elevated CO₂. Data are means ± sd (n = 4), and each replicate consisted of a pool of 30 to 50 plants. Black bars with single asterisks indicate significant differences at P < 0.05, and those with double asterisks indicate highly significant differences at P < 0.01 (Student’s t test). FW, Fresh weight. [See online article for color version of this figure.]