What Is Apical Dominance in Plants? How the Shoot Tip Controls Branching

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What is apical dominance in plants? Apical dominance is the way a growing shoot tip holds back the buds that sit lower on the same stem. In many plants the growing shoot apex inhibits the outgrowth of axillary buds, and that suppression keeps the plant growing mainly up one main stem. This article explains what apical dominance is, why it helps a plant, which plant hormones are involved, and where the two research reviews we checked stop. Both are PubMed Central articles that we opened on 2026-10-27.

Quick answer

• Apical dominance is when the apical bud or shoot tip inhibits the outgrowth of the buds below it. One review defines it as “when growth of the lateral bud is inhibited by the growing apical bud/shoot.”
• It lets a plant “focus resources into the main axis of growth,” according to one review, while dormant buds stay ready for recovery.
• Auxin, a plant hormone, is the classic signal. A second signal, cytokinin, acts against auxin in this process.
• Sugars are now also linked to the process. The second review says sugars have a major role that emerged from modern experiments.

How we chose

We chose two research reviews that cover apical dominance directly. The first is titled “Auxin, cytokinin and the control of shoot branching,” and the second is titled “Lessons from a century of apical dominance research.” We opened both on 2026-10-27 with curl, and both returned HTTP 200. The sentences below are quoted from the fetched text and are the basis for each factual claim.

What apical dominance means

The first review gives the basic observation. It states that “In many plants the growing shoot apex inhibits the outgrowth of axillary buds, a phenomenon termed ‘apical dominance’.” The second review gives a formal definition and a short description of what the term covers. It explains that “Apical dominance : also termed paradormancy, is when growth of the lateral bud is inhibited by the growing apical bud/shoot.” It also states that “Apical dominance occurs when a shoot tip suppresses axillary bud outgrowth and restricts the number of branches.”

The second review adds some history. It says that “The process of apical dominance by which the apical bud/shoot tip of the plant inhibits the outgrowth of axillary buds located below has been studied for more than a century.” The same review explains that much of the early work used herbaceous plants, noting that the experiments of the physiology era “frequently involved studies of herbaceous plants with strong apical dominance.”

The term describes one part of branching, not all of it. The second review states that “However, apical dominance is only one aspect of the processes controlling shoot branching, particularly in tree species.”

Why the plant benefits from it

The first review explains the advantage in one sentence. It states that “Apical dominance allows plants to focus resources into the main axis of growth, while activation of dormant buds allows for recovery after damage or loss of the main shoot.” In other words, the plant grows its main stem first, and the side buds are kept in reserve.

The reserve has a practical meaning. The first review says that activation of dormant buds allows for recovery after damage or loss of the main shoot. If the main shoot is damaged, buds that were held back can begin to grow, which lets the plant rebuild its branching pattern.

The hormone signals: auxin and cytokinin

The first review states the older view plainly. It says that “It has been known for a long time that auxin is a major signal for apical dominance.” The review treats auxin as the main message that restrains the side buds.

The first review also describes a second hormone. It states that “Thus, CKs antagonize auxin in apical dominance.” The abbreviation CK refers to cytokinin, and the word antagonize means that cytokinin works against auxin in this setting. The review describes a model in which one role of auxin is to repress local production of cytokinin. The model is phrased as “one role of auxin in apical dominance is to repress local biosynthesis of CK in the nodal stem.”

The review also describes an experiment that supports the link. It states that in bean and chickpea, “CK levels in the xylem sap were higher after decapitation,” and then adds that “this increase could be prevented by application of auxin to the decapitated stump.” Removing the shoot tip raised cytokinin, and putting auxin back on the stump prevented that rise. That result fits the balance model described above.

What changed in the research

The second review describes how the explanation has changed over time. It states that “During the physiology era, auxin was thought of as the master regulator of apical dominance acting indirectly to inhibit bud outgrowth via unknown secondary messenger(s).” That view placed auxin at the center of the story.

Later work added another layer. The second review states that “The re-discovery of the major role of sugars in apical dominance emerged from modern physiology experiments and involves ongoing work with genetic material affected in sugar signalling.” So the newer picture includes sugar signaling alongside hormones, and the review says that work is still ongoing.

The second review also notes that the classic distinction still matters. It says that “in his major review, Cline (1997) makes a strong distinction between apical dominance and correlative dominance.” The sources treat these as related but separate ideas, so the term apical dominance should be used with care.

Frequently asked questions

Is apical dominance the same as a dormant bud?

No. The second review defines apical dominance as “when growth of the lateral bud is inhibited by the growing apical bud/shoot.” The bud is held back by the shoot tip, and the review also describes activation of dormant buds as a recovery route after damage.

What hormone is most closely linked to apical dominance?

The first review says that “It has been known for a long time that auxin is a major signal for apical dominance.” Cytokinin is also part of the picture, because the review states that “Thus, CKs antagonize auxin in apical dominance.”

Does apical dominance only happen in herbaceous plants?

No, but much early research used herbaceous plants. The second review states that apical dominance is “only one aspect of the processes controlling shoot branching, particularly in tree species.” The review describes tree branching as a broader process.

Why does cutting the shoot tip make side branches grow?

The first review’s decapitation experiment shows the hormone change. It reports that cytokinin levels rose after decapitation, and that application of auxin to the stump could prevent the rise.

Is sugar part of apical dominance?

The second review says that “The re-discovery of the major role of sugars in apical dominance emerged from modern physiology experiments.” The review presents sugar as part of current research rather than a settled rule.

What we could not verify

The two reviews explain the hormone and sugar picture in general terms, but they do not give a single set of rules that applies to every species. We could not verify how the process works in a specific garden plant from these sources alone, so this article makes no species-specific claims.

What the sources do not say

The sources do not give pruning instructions, cut positions, or timing for any crop. They do not describe how gardeners should apply the concept to their own plants. For practical steps on starting plants that branch from the base, see how to transplant seedlings or how to grow tomatoes from seed to harvest, which cover the growing steps without relying on the research reviews here.

Sources

• Auxin, cytokinin and the control of shoot branching. PMC3091808, https://pmc.ncbi.nlm.nih.gov/articles/PMC3091808/. HTTP 200. Opened 2026-10-27.
• Lessons from a century of apical dominance research. PMC10400159, https://pmc.ncbi.nlm.nih.gov/articles/PMC10400159/. HTTP 200. Opened 2026-10-27.