2003 年 50 巻 2 号 p. 217-224
The synthesis of starch in wheat and barley is an important topic for research because of the exten sive utility of starch from these crop species in human and animal foods, and in industrial processes. Wheat and barley starches are highly characteristic due to their granular architecture and multi-modal granule size distribution. This granule architecture is important because it defines the ways in which wheat and barley starches behave during food processing. The core starch biosynthetic genes of wheat have been cloned and shown to exist as homeologous sets of genes represented on each of the three wheat genomes. While hexaploidyrepresents a major impediment to the selection of altered starch phenotypes by phenotypic screening, the availability of methods for identifying the products of homeologus genes from each of the wheat genes has provided methods for the selection of triple null lines from waxy, starch synthase ha, and branching enzyme I genes. In barley, direct phenotypic selection has resulted in the identification of waxy, amol and SSIIa mutations. In this paper, we review the state of knowledge of starch synthesis in wheat and barley and discuss the relationships between individual genes and their roles in starch biosynthesis.
