Measurement of the metal concentration in WT and mit-2 brown rice and polished seeds. a–d: Brown rice. e and f: Polished rice. a and e: Fe concentration. b and f: Zn concentration. c and g: Cu concentration. d and h: Mn concentration. Vertical bars followed by different letters are significantly different from each other according to the Tukey–Kramer test (p < 0.05; n = 4).