The importance of proteins in our diet is well recognized.
Cereals, the major group of our food crops have provided the
main source of energy and dietary proteins since the period
human ancestors resorted to domestication and cultivation of
crops. Their proteins have an imbalanced distribution of
essential amino acids which is due to the low content of these
amino acids in their predominant seed protein fractions. Various
strategies using conventional and molecular breeding towards
improvement of nutritional value of food crops have been
followed by plant scientists from time to time. The enormous
information generated through characterization studies of their
seed storage proteins and the development of new technologies
for genetic engineering and plant transformations have formed
the basis of improvement of grain quality in different cereals.
Genes for this purpose have been stably integrated and
efficiently expressed in transgenic cereals with useful results.
Successful approaches towards this end have included
manipulation of the expression levels of genes for homologous
proteins, use of genes for heterologous proteins, modification
of nutritionally inferior polypeptides by inserting codons for
essential amino acids in their genes etc. The present review
covers information on various achievements by different workers
through initial attempts in this direction.