Abstract

N. K. Matta, Arvinder Singh and Yogesh Kumar

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.