Recent Advances in the Biosynthesis and Metabolic Engineering of Storage Lipids and Proteins in Seeds

Abstract

During plant seed maturation, a key developmental step is the storage of biomolecules that remain within the embryo throughout dormancy and provide the necessary metabolites to support seedling growth. Seed storage lipids and proteins are among the most valuable materials for food, industrial, and other applications. Triacylglycerol (TAG) is the major storage lipid in most terrestrial plants and is an energy-dense molecule. TAGs are composed of one glycerol backbone esterified to three fatty acid (FA) tails and are highly abundant in the seeds of oleaginous plants. Seed storage proteins (SSPs) are polymers of amino acids (AAs) for nutrient storage and have a great variety of properties and compositions. Due to a growing global population and the climate-related need for petrochemical alternatives and non-animal protein sources, the demand for plant-sourced oils and proteins is steadily increasing. As such, there are strong research interests in exploring the biosynthesis and regulation of plant storage lipids and proteins and, subsequently, in using the knowledge gained to increase their accumulation and quality. In this chapter, we outline the current understanding of seed storage lipid and protein biosynthesis in higher plants, as well as promising genetic engineering strategies for optimizing the content and composition of these storage molecules.