Cereal Chem 61:305 - 310.  |  VIEW ARTICLE
Production of Multiple Forms of Alpha-Amylase in Germinated, Incubated, Whole, De- embryonated Wheat Kernels.

B. A. Marchylo, J. E. Kruger, and A. W. MacGregor. Copyright 1984 by the American Association of Cereal Chemists, Inc. 

Alpha-amylases produced in germinated wheat and incubated de-embryonated wheat kernels (Triticum aestivum cv. Neepawa), in the absence and presence of gibberellic acid (GA3), were analyzed qualitatively by polyacrylamide gel isoelectric focusing (PAG-IEF) and quantitatively by chromatofocusing. Alpha- amylases resolved by PAG-IEF were classified into three groups, designated GIII (pI values closest to cathode), GI (pI values closest to anode), and GII (intermediate pI values). Quantitative analysis revealed that, in germinating wheat, in the absence or presence of GA3, GIII components contributed the major proportion of activity, which decreased linearly with germination time concomitant with an increase in the proportion contributed by GI plus GII components. In the absence of GA3, alpha-amylase production in incubated de-embryonated wheat was significantly lower, with the GI plus GII groups contributing the major proportion of activity. Incubation of de-embryonated wheat in the presence of GA3 resulted in a substantial increase in alpha-amylase production primarily as GIII components. Relative proportions of components within the GIII and GI alpha-amylase groups were consistent throughout germination/incubation in the absence or presence of GA3. These results in conjunction with results previously reported indicate that GA3 differentially controls expression of the alpha-Amy-1 and alpha- Amy-2 genes, which code for production of the GIII and GI groups of alpha-amylase components in the aleurone.