Synthesis and secretion of α‐amylase by rice callus: Evidence for differential gene expression

Abstract

Rice seed callus expressed and secreted α‐amylase at high levels. Twenty percent of the protein secreted by the callus was αamylase. The callus secreted about 840 μg α‐amylase with 10.9 × 103 units of activity per gram dry weight callus per day. The α‐amylase from callus exhibited a more complex isoform pattern than the germinating seed α‐amylase. In addition, the level of mRNA expression by the five α‐amylase gene groups was markedly different between callus and the germinating seed. The rice callus culture has features which it attractive as a potential system for expression proteins in plant cell fermentation systems. Copyright © 1991 John Wiley & Sons, Inc.