Bioenergetic considerations in cereal breeding for protein improvement.

The bioenergetic implications of changing cereal grain protein concentrations and amino acid compositions by plant breeding are examined. It is shown that increased inputs of carbon assimilates and nitrogen are necessary when increasing protein concentration in cereal grains while maintaining high yields. Also, energetic requirements for obtaining endosperm proteins with a high lysine content in genotypes of maize and barley are slightly higher than in normal lysine stocks. The implications for plant breeding are discussed.