The activity of enzymes involved in combating ROS was
determined in the harvested leaves after 15 days of growth. The
choice of these enzymes was based on the fact that they have
been shown to respond to a variety of abiotic stress conditions
in plants. The results for APX, CAT, GR, and SOD activity are
shown in Table 1. From the data, it is possible to verify the ratio
of enzymatic activities between T and NT soybean leaves. We
found that GR exhibited the highest ratio. Taking into account
that all of the tested enzymes are involved in defence against
oxidative stress, such a result may be an indication that T leaves
are under different stress conditions when compared to NT
leaves. Another interesting result is that the SOD activity is ca.
45% higher in T leaves when compared to NT plants. As SOD is
involved in dismutation of the superoxide radical [24], it is easy
to hypothesise that high concentrations of this species are
produced in the T plants. This is particularly important because