|Title of host publication||Encyclopedia of Applied Plant Sciences|
|Editors||Brian Thomas, Brian G. Murray, Denis J. Murphy|
|Publication status||Published - 2017|
Developing seeds require uptake of nutrients from maternal tissues to supply energy and substrates for growth and maturation. Additional nutrients are required to lay down the sometimes considerable stores of carbohydrates, proteins, and lipids that enable seeds to germinate and undergo heterotrophic growth as seedlings before they become photosynthetically competent. Nutrients are delivered as assimilates into seeds via the seed coat and are then delivered to endosperm and embryo tissues via various mechanisms. Seeds act as powerful sink tissues that attract assimilates from primary source tissues via symplastic and apoplastic transport systems.