Abstract
Gibberellic acid enhances the synthesis of α-amylase in isolated aleurone layers of barley-seeds (Hordeum vulgare var. Himalaya). In the presence of 20 mm calcium chloride the amount of enzyme obtained from isolated aleurone layers is quantitatively comparable to that of the half-seeds used in earlier studies. After a lag period of 6 to 8 hours enzyme is produced at a linear rate. Gibberellic acid does not merely trigger α-amylase synthesis, but it is continuously required during the period of enzyme formation. Enzyme synthesis is inhibited by inhibitors of protein and RNA synthesis. Small amounts of actinomycin D differentially inhibit enzyme release and enzyme synthesis suggesting 2 distinct processes. Gibberellic acid similarly enhances the formation of ribonuclease which increases linearly over a 48 hour period. During the first 24 hours the enzyme is retained by the aleurone cells and this is followed by a rapid release of ribonuclease during the next 24 hour period. The capacity to release the enzyme is generated between 20 and 28 hours after the addition of the hormone. Ribonuclease formation is inhibited by inhibitors of protein and RNA synthesis. These inhibitors also prevent the formation of the release mechanism if added at the appropriate moment.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- KIRBY K. S. ISOLATION AND CHARACTERIZATION OF RIBOSOMAL RIBONUCLEIC ACID. Biochem J. 1965 Jul;96:266–269. doi: 10.1042/bj0960266. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Paleg L. G. Physiological Effects of Gibberellic Acid: I. On Carbohydrate Metabolism and Amylase Activity of Barley Endosperm. Plant Physiol. 1960 May;35(3):293–299. doi: 10.1104/pp.35.3.293. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SHUSTER L., GIFFORD R. H. Changes in 3'-nucleotidase during the germination of wheatembryos. Arch Biochem Biophys. 1962 Mar;96:534–540. doi: 10.1016/0003-9861(62)90332-6. [DOI] [PubMed] [Google Scholar]
- Varner J. E., Chandra G. R. HORMONAL CONTROL OF ENZYME SYNTHESIS IN BARLEY ENDOSPERM. Proc Natl Acad Sci U S A. 1964 Jul;52(1):100–106. doi: 10.1073/pnas.52.1.100. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Varner J. E. Gibberellic Acid Controlled Synthesis of alpha-Amylase in Barley Endosperm. Plant Physiol. 1964 May;39(3):413–415. doi: 10.1104/pp.39.3.413. [DOI] [PMC free article] [PubMed] [Google Scholar]