Fig. 7.

Changes in the concentrations of free amino acids in rice roots after application of ammonium. Rice seedlings were hydroponically grown in tap water for 11 d after sowing and transferred to nitrogen-free culture medium for 3 d. Then, the roots were dipped into the culture medium containing 1 mM KCl (light gray) or 1 mM NH₄Cl (dark gray) for 30 min. Roots were harvested in triplicate, and the amino acid contents were analyzed. Bars represent mean values with the SD. The detailed data are provided in Supplementary Table S3.