From Gene to Plate: Molecular Insights into and Health Implications of Rice (Oryza sativa L.) Grain Protein

Abstract

Rice is a staple food crop widely consumed across the world. It is rich in carbohydrates, quality protein, and micronutrients. The grain protein content (GPC) in rice varies considerably. Although it is generally lower than that of other major cereals, the quality of protein is superior. GPC and its components are complex quantitative traits influenced by both genetics and environmental factors. Glutelin is the major protein fraction (70-80%) in rice. Rice protein is rich in lysine, methionine, and cysteine along with other amino acids. Globally, Protein-Energy Malnutrition (PEM) is a major concern, particularly in Asia and Africa. Additionally, non-communicable diseases (NCDs) including diabetes, cancer, cardiovascular diseases, hypertension, and obesity are on the rise due to various reasons including changes in lifestyle and consumption patterns. Rice plays a very important part in the daily human diet, and therefore, substantial research efforts focus on the genetic characterization of GPC and understanding its role in the prevention of NCDs. The contribution of both rice grain and bran protein in improving human health is an established fact. The present study summarizes the different aspects of rice grain protein including its variability, composition, factors affecting it, and its industrial uses and more importantly its role in human health.

Keywords: QTL; amino acid; grain; health; protein; rice.

Figure 1

The global prevalence of Protein–Energy Malnutrition (PEM). Others include Oceania, Caribbean, Australasia, high-income Asia Pacific, and high-income North America. Source: [19].

Figure 2

Grain protein content in different types of rice (a); grain protein content in different stages of rice grain development (b). Protein content is expressed as dry grain weight. Source: [15,24,25,26,27,28,29].