Expressions of AtMTM1, AtMTM2, and AtMSD1under metal stresses
To elucidate the effect of metal stress on AtMTM1 , AtMTM2 , and AtMSD1 gene regulations, we transferred 2-week-old seedlings to buffers containing 100 μM of Mn (MnCl2), Fe (Fe citrate), Cu (CuSO4), Zn (ZnSO4), Mg (MgSO4), and Ca (CaCl2) for 24 h with gentle shaking (Figure 6) .
Compared to the unstressed condition, AtMTM1 , AtMTM2 , andAtMSD1 expressions responded positively to most metal stresses by qPCR. The 100 μM Mn treatment caused no significant effect onAtMTM1 expression. AtMTM2 was markedly responsive to Cu stress compared with AtMTM1 and AtMSD1 . Generally, all three genes were up-regulated synchronically under metal stresses.