**3.7 Plant antioxidant defense against flooding**

Numerous crop species have displayed their capability to continue under the flooded or waterlogged situation for brief or even extended durations through triggering antioxidant defense mechanisms. An experiment was conducted by Li et al. [92], using18 maize genotypes which were subjected to waterlogged conditions and revealed that after 2 days of stress, 12 genotypes had 19–57 percent greater SOD activity, 13 genotypes had 19.16–106.96 percent greater POD activity, and only 9 genotypes had 26–57 percent greater CAT activity. In sesame seedlings under waterlogged conditions, lower AsA content, while higher GSH and GSSG content, as well as H2O2 content, was detected in a time-dependent way [93]. During extended (8 days) WL stress, although, AsA-GSH cycle enzymes were not controlled similarly, with considerably increased APX and MDHAR activity and considerably decreased DHAR and GR activity.

Furthermore, Park and Lee [94] found that when the Antarctic plants*. antarctica* was exposed to waterlogged (for 7 days), it accumulated about 52 percent more H2O2 and had 91 percent more CAT activity than controls.
