Genetic determination of the developmental program for maize scutellar alcohol dehydrogenase: Involvement of a recessive, trans‐acting, temporal‐regulatory gene

Abstract

AbstractThe developmental program of alcohol dehydrogenase (ADH) activity in the scutellum of maize strain R6‐67 is different from that of W64A. The level of scutellar ADH activity in R6‐67 remains relatively high during the course of early sporophytic development as compared to the commonly observed pattern. In the typical inbred strain W64A, the activity of ADH declines substantially during that period. The variance values from the crosses between R6‐67 and W64A reveal that the trait is under genetic control. Detailed genetic analysis suggests that a single gene is responsible for the altered developmental program of ADH activity in R6‐67. This gene meets the criteria for temporal regulatory genes and is different from Adh2, the structural gene which codes the ADH‐2 isozyme. We have designated this gene as Adr1 (alcohol dehydrogenase regulator, #1). Adr1 is unlinked to Adh2. There is no de novo synthesis of ADH in the scutellum during germination, and the difference in the activity level reflects the difference in the amount of enzyme protein as demonstrated by density labeling and rocket immunoelectrophoresis. Thus, it appears that Adr1 may regulate the degradation of ADH.