cDNA cloning and induction of the alcohol dehydrogenase gene ( Adh1 ) of maize

Abstract

C[complementary]DNA clones of Adh1, one of 2 genes encoding alcohol dehydrogenase (ADH; alcohol:NAD+ oxidoreductase, EC 1.1.1.1) in the maize genome, were isolated. They were derived from mRNA extracted from anaerobically treated roots of maize seedlings. Identification was initially made on the basis of MW and electrophoretic properties of the in vitro polypeptide obtained in hybridization-release-translation experiments. The identification was confirmed by antibody precipitation and by the use of maize stocks having different genetic constitutions at the Adh1 locus. The sequence of the longest cDNA segment, .apprxeq. 900 base pairs, was determined and appears to code for 168 COOH-terminal amino acids and to have a 3'' nontranslated region of 364 base pairs. Reverse Southern hybridizations established that 2 different Adh1-S stocks produce a mRNA of 1650 nucleotides, whereas an additional mRNA of 1750 nucleotides is produced in 3 Adh1-F stocks. A 50-fold increase in Adh1 mRNA level occurs during anaerobiosis, reaching a maximum at 5 h. Return to aerobic conditions indicates a half-life of more than 18 h for the anaerobically induced Adh1 mRNA.