The Role of Sugar Demand in Apical Dominance: Branching in a New Direction (2015-2017)

For centuries, people around the world have made use of the knowledge that pruning the growing tips of shoots causes buds on the stem below to grow out into branches. Yields in crop, horticulture and forestry industries depend on shoot architecture. Since the discovery of auxin in the 1930s, shoot branching has been thought to be regulated by plant hormones. However, we propose a new theory whereby shoot tip demand for sugar is predominant in apical dominance; enhanced sucrose, a mobile sugar, is necessary and sufficient for the initial growth of buds. This project will expand this theory, revealing underlying components involved in sucrose action and describe how the network of sugar demand and hormones acts to control shoot architecture.