Changes in the metabolic profile and nutritional composition of rice in response to NaCl stress

Abstract

Salinity is a major abiotic stress that adversely affects crop productivity and quality. In this study, the metabolic profile and nutritional composition of rice in response to NaCl were analyzed. The plants were exposed to stressed or unstressed conditions, and their metabolic changes were examined in the shoots, roots, and grains collected at different growth stages. The levels of nutrients and anti-nutrients, including proximates, amino acids, fatty acids, minerals, vitamins, and phytic acid, were also determined for the grains. Application of NaCl significantly decreased the shoot and root growth and induced metabolic alterations at the tillering stage. During the heading stage, only the root metabolites were influenced by NaCl, and no metabolic variations related to salinity were found in the shoot, roots, and grains at the ripening stage. Nutritional analysis of the grain samples revealed that the amounts of linolenic acid and tricosanoic acid were significantly reduced while those of copper, sodium, and phytic acid were enhanced in response to stress. However, except for sodium, those differences were not great. Our results suggest that although NaCl-salinity influences the phenotypic and metabolic profiles of rice shoots and roots at the tillering stage, this impact becomes negligible as tissue development proceeds. This is especially true for the grains. Compositional analysis of the grains indicated that salinity induces some changes in fatty acids, minerals, and anti-nutrients