3.2.4 Effects of different concentrations of exogenous Zinc on
the contents of APX，AsA and GSH activities in leaves ofDendrobium nobile
As can be seen from Figure 4a, the content of APX increases with the
increase of zinc treatment concentration. At 14 days of treatment, when
the zinc concentration was less than 100 μmol/L, there was no
significant change in APX content compared with the control group.
However, with the prolongation of the treatment time, when the zinc
concentration is greater than 100 μmol/L, the APX content of the
treatment group is significantly higher than that of the control group.
At the same time, it can be seen from the figure that when the zinc
concentration is in the range of 200-1000 μmol/L, after 14 days of zinc
treatment, it is significantly increased compared with the control. The
peak value of APX appeared at zinc concentration of 400μmol/L and
treatment time of 14 days.