Improvement of the methionine content of seeds through modification of the Phaseolus vulgaris seed protein arcelin-5a

Abstract

Plant seeds represent the primary nutritional protein source for humans as well as animals. The seed protein fraction is, however, unbalanced with reference to the needs of humans as well as domesticated monogastric animals because essential amino acids are present at levels insufficient for dietary requirements. Compared to the FAO reference protein, cereal proteins tend to be low in lysine and tryptophan content while legume seed proteins contain low amounts of the sulfur-containing amino acids, methionine and cysteine. In cereals, this deficiency could be partly overcome through conventional breeding efforts. The lysine concentration was improved by genetic suppression of the lysine-poor endosperm proteins, in favor of increased amounts of other proteins rich in lysine. This strategy is not useful in legumes since virtually all known legume seed storage proteins contain low amounts of the sulfur-containing amino acids. Recent developments in recombinant DNA technology offer alternative molecular approaches to modify the amino acid composition of seed proteins.

Date of Award	2002
Original language	English
Supervisor	Geert Angenon (Promotor)