The nutritional health and well-being of humans are entirely dependent on plant foods either directly or indirectly when plants are consumed by animals. Plant foods provide almost all essential vitamins and minerals and a number of other health-promoting phytochemicals. Because micronutrient concentrations are often low in staple crops, research is under way to understand and manipulate synthesis of micronutrients in order to improve crop nutritional quality. Genome sequencing projects are providing novel approaches for identifying plant biosynthetic genes of nutritional importance. The term 'nutritional genomics' is used to describe work at the interface of plant biochemistry, genomics, and human nutrition.