Alcohol Dehydrogenase and Pyruvate Decarboxylase Activities in Flood‐Tolerant and Susceptible Corn Seeds during Flooding1

Abstract

AbstractEarly planted corn (Zea maysL.) is frequently subjected to flooding stress, especially in poorly drained soils. This study characterizes the role of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) enzymes in the flooding susceptibility of corn seeds; PDC and ADH activities were assayed in a flood‐tolerant (A632) and a flood‐susceptible (Mo17) inbred during flooding at 10 and 25 °C. Each inbred consisted of two seed lots possessing different germination levels (95 and 75% germination). Flooding induced an increase in the activity of both enzymes. However, the increase was greater and sustained longer for ADH than PDC. The maximum level of ADH activity achieved was similar in both inbreds, but was greater in the high‐quality than in the low‐quality seeds. Since the highquality seeds survived flooding longer than the lowquality seeds, no correlation between flooding susceptibility and maximum ADH activity was observed. The two inbreds also exhibited similar ADH isoenzyme patterns. These data indicate that flooding susceptibility is not associated with PDC or ADH activities in corn seeds.