Alpha-amylase synthesis can be induced in wheat and barley half-seeds by addition of gibberellic acid (GA) to the incubation medium. In maize, induction in de-embryonated kernels by exogenous GA has been reported in some studies but not others.
Alpha-amylase induction was investigated in maize by measuring activity in extracts from whole and de-embryonated kernels incubated with and without GA during germination. Alpha-amylase activity was first detected on the 3rd day of germination in whole kernels and GA-treated endosperms and on the 4th day in the controls. Thereafter both whole kernels and GA-treated endosperms followed approximately the same time course in α-amylase activity with the control lagging a day behind. Studies indicated that maximum α-amylase activity occurred on the 7th day in whole kernels and GA-treated endosperms and the 8th in control endosperms.
Maize α-amylase was purified using differential solubility, column chromatography, glycogen precipitation and polyacrylamide gel electrophoresis, of these, the best purification method was glycogen precipitation.
Maize α-amylase exhibited isozymes. The isozyme patterns were qualitatively similar in all samples and throughout incubation. Wheat and barley α-amylase isozymes have been divided into two groups on the basis of a number of characteristics. Genetics analysis revealed these isozymes to be the result of two multigene families. To shed light on the genetic basis of the maize α-amylase isozymes, physicochemical characterization was initiated. Studies of pH and temperature profiles and optima showed no differences between maize isozymes. The pH optima was pH 5 and the temperature optima was about 37°C. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/80140 |
| Date | January 1987 |
| Creators | Zimmerman, Rosalind Kane |
| Contributors | Botany |
| Publisher | Virginia Polytechnic Institute and State University |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | en_US |
| Detected Language | English |
| Type | Thesis, Text |
| Format | viii, 85 leaves, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 16679417 |
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