Chapter 4 - Role of plant sulfur metabolism in human nutrition and food security

Abstract

Sulfur is an indispensable nutrient for all organisms as a constituent of amino acids cysteine and methionine and a range of vital cofactors and coenzymes. Because animals and humans cannot assimilate the most common sulfur source, sulfate, they are dependent on a supply of reduced sulfur, mainly in the form of the essential amino acid methionine. Plants are capable of sulfate assimilation and, therefore, plant proteins are the most important source of sulfur in animal and human diets. The growing human population and the changing environment are great challenges for ensuring food security for future generations. Sulfur is one of the nutrients under risk of being deficient in food, because of the reduced atmospheric deposits and the reduction of protein content in grains as a consequence of increased carbon dioxide concentration in the air. To mitigate the potential sulfur deficiency, more has to be understood about the impact of the changing environment on crop yields and quality. In this review, the current knowledge of the impact of the changing environment on plant sulfur metabolism will be reviewed and the consequences for human nutrition and food security will be discussed with the aim to identify knowledge gaps and propose research directions to ensure sufficient sulfur in food for future generations.