Source-sink relationships

Abstract

Life on earth depends on the growth and survival of plants. In order for plants to grow and develop effectively, coordination between sources and sinks is required. Source organs provide a net uptake of resources whilst sink organs have a net drawdown of resources. Molecular mechanisms regulate the relationship between sources and sinks. These molecular mechanisms include carbon- and nitrogen-containing metabolites, plant hormones, and genes. Sources and sinks for both carbon and nitrogen are key contributors to plant growth, and these regulate themselves and one another via feedback, feedforward, and crosstalk mechanisms. Our understanding of the relationships between sources and sinks is increased by experimental manipulations of the source-sink balance. To bring about increases in crop growth and yield, a holistic view of sources and sinks must be developed, including the molecular mechanisms underpinning the relationships between them. Mathematical modelling can be an effective tool for providing this unified perspective.