What is Gibberellin?

Mary McMahon
Mary McMahon

Gibberellin is a type of plant hormone which regulates growth. There are 126 known gibberellins, divided into two classes, and many more may be discovered in the future. Plants produce these hormones naturally through biosynthesis as they grow, ensuring that they have the hormones they need to develop normally, and these hormones can also be applied to plants by gardeners and farmers to achieve specific desired outcomes.

Man mowing the grass
Man mowing the grass

Existence of gibberellin was first hypothesized in 1926, when Japanese researchers were struggling to understand why some rice plants would randomly shoot up to such great heights that they would collapse, becoming impossible to harvest. They discovered that the plants were infected with a fungus which seemed to affect growth, and in 1935, a Japanese researcher successfully isolated gibberellin for further study.

One of the primary functions of gibberellin in a plant is to regulate the growth of the stems. Many members of the cabbage family, for example, release gibberellin when they “bolt” to produce long flowering stalks. These hormones can also influence sex expression, and they appear to be capable of breaking dormancy and promoting germination of seeds. These traits make gibberellins very useful for people who are attempting to tightly control their crops.

Applications of gibberellin to crops can also allow them to produce seedless fruits. The ever-popular seedless grape, for example, wouldn't fully develop and mature without an application of hormones at the right time. These hormones can also force plants to flower, which can be useful in settings where the timing of flowering needs to be precise.

When plants are bred as dwarf cultivars, these cultivars have genetic variations which either inhibit the production of gibberellin, or prevent the plant from utilizing the hormone as it normally would. The genes which deal with gibberellin have been isolated in many plant species to provide more information about how dwarf cultivars work, and how they can be more precisely bred and controlled for reliable performance in the garden or on the farm. In some cases, applying gibberellin to a dwarf plant will cause it to grow like full-sized relatives.

Understanding the mechanics of plant hormones is important for a number of reasons. In the agricultural industry, knowing how, when, and why hormones work can be critical to long-term success, and it's also interesting from a purely scientific standpoint. Many researchers around the world work on gibberellins, identifying new varieties and exploring existing types for more information.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


@ddljohn-- I'm not sure about genetic engineering but the giberellin hormones that people inject to plants is not the same exact hormone that plants produce naturally. It is a synthetic hormone, meaning that it is produced in the lab.

So even thought it does the same thing as the natural gibberellin hormone found in plants, it's still unnatural. In that sense, I do think that it might have different affects on the plants and on us when we consume it. But scientists don't know about the long term consequences of genetically engineered plants or synthetic hormones yet. So I don't think we know for sure whether it has any negative effects on our health or not.


Many people who support organic farming say that genetically engineered fruits and vegetables are not good for our health.

Since gibberellin hormone is naturally produced by plants, is it considered genetic engineering? I don't know what genetic engineering means exactly, but I think it's about changing the genetic makeup of plants. Does giving plants gibberellin hormone change their genetic makeup? And is it dangerous?

I feel that it shouldn't be dangerous because the plant should be producing that hormone anyway but is unable to. At the same time though, I don't know how right it is to load up fruits and vegetables with this hormone and grow them to sizes that they would never reach naturally.

What do you think?


I saw pictures of plants where some were given gibberellins and some were not. The differences between them were huge! This was an experiment to see how growth of plants would be impacted by use of gibberellin. They experimented on several corn plants and cabbage plants. The corn which was not given any gibberellin was tiny, whereas the ones which were had grown really long. The same was true with the cabbage.

The other interesting part is that the fruit was also better quality and was twice as big in size. All the corn which were given gibberellin were full but the other one had a lot of empties. They experimented with grape as well and the grapes were much bigger with gibberellin.

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