Effect of H2S and rhizobia on antioxidant enzyme
system in soybean plant leaves under water deficiency
As shown in Fig. 6A, with the decrease of water content, the SOD
activity showed a trend of increased first and then decreased by control
and NaHS treatments, and the SOD activity was decreased in varying
degrees by Q8 and Q8+NaHS treatments (Fig. 6A). Under the three water
conditions, the POD activity was sharply increased by Q8 and Q8+NaHS
treatments. With the decrease of water content, the POD activity was no
apparent changed under control treatment, but NaHS treatment showed a
trend of increasing first and then decreasing. Moreover, the POD
activity was obviously inhibited by Q8+NaHS treatments under MW and SW
conditions (Fig. 6B). The CAT activity was substantially enhanced by
four treatments under SW condition compared with NW condition. In
contrast, the CAT activity was increased by 5.0 and by 5.3-fold under
the Q8 and Q8+NaSH treatments compared with control under SW condition,
respectively (Fig. 6C). In addition, with the decrease of water content,
the APX activity was notably enhanced by control and Q8+NaHS treatments.
However, the APX activity of NaHS and Q8 treatments displayed a tendency
to decrease initially and then increase, and no matter what the water
content, the APX activity by Q8+NaHS treatment was higher than control
(Fig. 6D).