Apical dominance models can generate basipetal patterns of bud activation

An important aspect of plant development is the order in which lateral buds are activated to produce branches. This order may manifest itself, for example, in the gradient of branch lengths, or in the flowering sequence. One progression type is acropetal, with the lateral buds activated from the bottom up. Other plants exhibit a basipetal sequence of bud activation, with a downward progression of branch development. More complex, mixed sequences also occur, with the activation sequence converging towards or diverging away from the central part of the shoot axis. The acropetal progression can be simply explained by postulating that lateral buds are activated in the same order in which they were created (possibly with some delay). However, basipetal progression eludes such a simple explanation, raising the question of what mechanisms may be responsible. As details of the underlying signaling processes, and their interplay with development, are difficult to observe directly, simulation models are helpful in integrating diverse experimental data, in highlighting the dynamic relations between local processes and the resulting emergent structures, and in assessing plausibility of alternative hypotheses.