Abstract
Maize kernels contain several types of storage proteins. By far, the most abundant are prolamins, zeins, a unique storage protein found only in cereals. Because of their abundance, zeins have a profound influence on human and livestock nutrition. These proteins also appear to influence the mechanical strength of the kernel, which is important for harvesting and storage, and they affect the functional properties of food products made from corn. While a great deal of research has been devoted to the characterization of genes encoding zeins and the mechanisms by which the proteins are synthesized and stored in endosperm cells, many important questions remain regarding their structure, the regulation of the genes encoding them, and how they influence the formation of the hard, vitreous regions of the mature kernel. This chapter reviews what is known about maize storage proteins, and describes important questions that remain to be answered about their synthesis and functions in the grain. It also considers technical approaches for altering the storage protein content of maize kernels to increase the level of lysine, the most limiting essential amino acid for monogastric animals.