Structural and permeability properties of the soybean seed coat

Abstract

The seed coat is a composite structure that serves as a conduit for nutrient acquisition for the developing embryo. Upon seed desiccation and maturation, the seed coat provides cover and protection for the embryo and may impose dormancy or trigger germination by controlling water uptake. For crop plants such as soybean, traits determined by the seed coat impact the overall quality of the seed and the utility of its derived products. There are remarkable examples of unusual genetic mechanisms that control seed coat pigmentation, lustre, and cracking that have been recently described in soybean. Studies on seed permeability to water have resulted in the formulation of new hypotheses to account for variation of this trait. This review summarizes the current advances in our understanding of the structural properties of the soybean seed coat with an emphasis on the control of permeability to water in mature seeds.