In general, the time course of the activities of APX, total
ASA, ASA, reduced ASA and total glutathione was characterized
by an increasing trend after flooding, especially for
APX in the plant roots with the highest content as compared
to other antioxidants. In other words, APX is far superior
to other antioxidases as a flooding-tolerance enzyme.
Therefore, the present study demonstrates that flooding
may enhance the levels of the enzymatic scavenger APX.
This indicates that the roots of flooded plants maintained a
certain level of H2O2 scavengers, which consumed at least
a part of the H2O2. Therefore, the increased H2O2 in the
roots of flooded plants was far less then O2
−,•EO2 and
•OH, especially in the regions of the brownish roots. Plant
roots under waterlogged conditions generate H2O2 that may
then be removed by APX. For this reason, APX activity
can serve as criteria for evaluating the flood tolerance of
plant roots. We currently focus on proteomics as a tool for
gene discovery and molecular breeding in relation to floodtolerant
tomatoes. Analyzing the flood-responsiveness of
APX from the roots of the tomatoes and eggplants is a
process, which is still being carried out.