Submitted to: Plant Physiology
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/1995
Publication Date: N/A
Technical Abstract: Alpha-amylase is believed to be the only enzyme capable of initiating degradation of native starch granules in cereals. However recent evidence suggests that alpha-glucosidase is also capable (Sun and Henson, 1990. Plant Physiol, 94:320-327; Konishi et al, 1994. Biosci Tech Biochem 58:135-139). Together the two enzymes act synergistically. We previously isolated and characterized a 2.6 kb alpha-glucosidase cDNA clone from GA-treated barley aleurone tissue (Tibbot and Skadsen, 1995. Plant Mol Biol, submitted). The deduced amino acid sequence identifies the enzyme as belonging to family 31 of the glycosyl hydrolases. This family includes human lysosomal and Candida tsukubaensis alpha-glucosidases, in addition to others. Northern blots demonstrate that the gene is positively regulated by GA in aleurones. The expression pattern of the mRNA is almost identical to low-pI alpha-amylase. To further explore the GA regulation, we isolated the genomic clone from a lambda-ZapII library containing genomic DNA that had been digested to completion with SspI and then size-fractionated. The results of our findings will be presented.