Summary
The terminal bud suppresses lateral buds through auxin, shaping plant architecture.
In depth
Auxin from the shoot tip moves down, inhibiting lateral buds directly and via cytokinin and strigolactone regulation. Pruning removes the tip and encourages bushiness.
Cytokinins from roots promote lateral bud outgrowth; strigolactones suppress them. Removing the apical bud shifts the balance. Gardeners prune to change shape and flowering.
Example: hedge trimming encourages dense growth.
The apical bud suppresses lateral buds through auxin transport down the stem, which maintains inhibition by strigolactone signalling and reduces cytokinin supply to buds. When the tip is removed (pruning), auxin supply stops, and lateral buds grow, making the plant bushier. Applying auxin to the cut surface restores inhibition, as shown by Thimann and Skoog (1933).
Apical dominance allows plants to prioritise height and light capture. Its strength differs among species: conifers have strong dominance (Christmas tree shape), and shrubs have weak. Gardeners use pinching to promote branching, and hedge trimming relies on it. Branching can also be controlled by nutrient status and sugar signals.
Frequently asked questions
What is Apical Dominance?
The terminal bud suppresses lateral buds through auxin, shaping plant architecture.
Which area of biology covers Apical Dominance, and how advanced is it?
Apical Dominance is one of the 56 topics in Plant Biology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Plant Hormones, Auxin and Phototropism, Abscisic Acid and Drought.
Why does Apical Dominance matter?
Understanding it helps to shape crops and ornamental plants for yield.
Can you give an example of Apical Dominance?
Pinching out growing tips makes bushier herbs.
What should I learn before Apical Dominance?
Work through the Beginner topics in Plant Biology first, such as Plant Kingdom, Photosynthesis, Chlorophyll, then return to Apical Dominance. Advanced topics assume the Intermediate vocabulary.
What topics are related to Apical Dominance?
The closest topics to Apical Dominance are Plant Hormones, Auxin and Phototropism, Abscisic Acid and Drought, Roots. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Apical Dominance?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Apical Dominance. To practise the whole of Plant Biology, use the Plant Biology quiz.
How is Apical Dominance different from Plant Hormones?
Apical Dominance: The terminal bud suppresses lateral buds through auxin, shaping plant architecture. Plant Hormones: Auxin, gibberellin, cytokinin, abscisic acid and ethylene regulate growth, development and responses. Read both side by side and note what each one explains.
How should I study Apical Dominance step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Plant Hormones and explain the difference aloud. Finally, take the Plant Biology quiz and come back to this page for any question you miss.