A new candidate protein for high lysine content in wheat grain

Abstract

Lysine is the most limiting essential amino acid in cereal grains, so that grain lysine content is important for human nutrition and livestock growth. Translation elongation factor 1α (EF-1α) from cereal embryo was recently reported to be rich in lysine, and the possibility of using this protein as a marker for feed quality was explored in maize. In this study we used immunochemical methods to investigate the relationship between the content of EF-1α and other proteins from wheat germ and lysine content in both hexaploid (bread) wheats and diploid wheat progenitors to the wheat A-genome. The levels of grain lysine, as well as their variation between lines or cultivars, were greater for the diploid wheats. While there was a significant correlation between the levels of EF-1α and grain lysine content, the binding of antibodies to a protein of Mr 37 000 showed a higher correlation. This protein was characterised by amino acid sequencing as fructose 1,6-bisphosphate aldolase. The possibility of using fructose 1,6-bisphosphate aldolase as a marker for feed quality and development of a simple ELISA for quantification of lysine in wheat is demonstrated. © 2000 Society of Chemical Industry