The Interaction Effects of Flooding and Kinetin on Growth Criteria, Chlorophyll Content, and 5-Aminolevulinic Acid Dehydratase Activity in Corn Seedlings

The interaction effects of kinetin and flooding on growth indexes, chlorophyll content, and the activity of 5-aminolevulinic acid dehydratase (ALA-D; EC 4.2.1.24) in seedlings of corn (Zea mays L. cv. 704) were investigated. Samples were taken 48, 96, 144, and 192 h after the start of treatment. Growth criteria (root length, shoot height, and dry weight) were inhibited more in flooded plants than in control plants. The pattern of growth changes was similar to chlorophyll a and b, as well as ALA-D activity. The exogenous application of kinetin (100 ppm) nullified the resulting decrease in growth and chlorophyll, but only partially reduced the suppression in ALA-D activity. These results indicate that recovery of flood-induced injury and restoration of normal conditions was maintained either partially or completely by the application of kinetin. This recovery might have been the result of the action of several hormones, which can trigger internal cellular metabolism and induce changes in the ratios of growth regulators.