Submitted to: Association for Women in Science of Central Ohio
Publication Type: Proceedings
Publication Acceptance Date: 10/12/1997
Publication Date: N/A
Technical Abstract: Alcohol-dehydrogenase (ADH) in higher plants is encoded by a small gene family, usually with two members. These genes are inducible by hypoxia, and may play an important role in the mechanism of flooding tolerance. We have isolated three distinct ADH cDNA clones from soybean (cv Keller) anaerobic cotyledons by RT-PCR. Sequencing showed that the three clones have 75-95% DNA sequence and 79-92% amino acid sequencehomology to each other. Compared to other plant ADH proteins, amino acid sequences deduced from the cDNA are most similar to other legumes and distantly related to monocot alcohol-dehydrogenases. Based on the cDNA sequences and Southern hybridization data, we propose a four- or possibly five-gene model for soybean Adh. Analysis of RNA from aerobic and anerobic cotyledons, hypocotyls, leaves and roots showed the differential expression pattern of the three Adh genes. One of the genes expressed only in hypoxic roots. The other two genes expressed in all hypoxically treated organs. Two members of the Adh gene family were isolated from a soybean genomic library, the genomic clones resemble two of the three cDNA clones. The introl/exon order and the exon sizes in the genomic clones were the same as in other plant Adh genes. Sequencing of the upstream region of one of the genomic clones revealed the presence of ubiquitous promoter-specific motifs, like the TATA-box and the pyrimidine box. Cis-regulatory elements, which may be involved in the differential expression of this gene and have been found previously in maize and Arabidopsis Adh promoters, are present on the putative soybean Adh promoter as well.