Submitted to: Plant Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2007
Publication Date: 11/30/2007
Citation: Bhave, M., Morris, C.F. 2008. Molecular genetics of puroindolines and related genes: allelic diversity in wheat and other grasses. Plant Molecular Biology 66:205-219. Interpretive Summary: Kernel hardness (texture) is an important end-use quality trait in wheat. Variation in hardness is associated with variation in puroindoline genes. In this report, all of the information now available on Puroindoline genes in wheat is reviewed. New developments in molecular genetics of wheat Puroindoline genes is reviewed. In the past decade, much has been discovered about how the presence and sequence variation of Puroindoline genes affects wheat texture, and whether variants of this gene are potentially useful. The way similar genes affect barley, rye, and other cereal grains is also reviewed.
Technical Abstract: The hardness or texture of cereal grains is a primary determinant of their technological and processing quality. Among members of the Triticeae, most notably wheat, much of the variation in texture is controlled by a single locus comprised of the Puroindoline a, Puroindoline b and Grain Softness Protein-1 (Gsp-1) genes. Puroindolines confer the three major texture classes of soft and hard common wheat and the very hard durum wheat. The proteins products of these genes interact with lipids and are associated with the surface of isolated starch (as a protein fraction known as ‘friabilin’). During the past ten years a great diversity of alleles of both Puroindoline genes have been discovered and significant advances made in understanding the relationship between the gene presence, absence, sequence polymorphism and the texture of cereal grains. Efforts have also focussed on Puroindolines and the linked Gsp-1 genes in diploid progenitors, other Triticeae grasses and synthetic wheats in order to understand the evolution of this gene family and find potentially useful variants. The puroindoline homologues in cereals such as barley and rye are also receiving attention. New developments in molecular genetics of puroindolines in wheat, the related Triticeae grasses and other cereals are discussed here. The state of affairs regarding the biochemical basis of kernel texture, other roles of puroindolines such as antimicrobial activity and potential applications of puroindolines are discussed in an accompanying review.