Are Terpenes Just for Taste and Smell?

A quick look into how terpenes protect plants by deterring mammalian predators, recruiting bodyguards, and fighting off insects.

Perhaps the most popular knife since the end of World War 2 has been the Swiss Army knife. It’s distinct red color and array of pivoting gadgets makes it as memorable as it is functional.

I remember getting a Swiss Army knife as a child and not knowing what half of the pivoting gadgets were supposed to be used. The scissors made sense, the blades as well. But what was this dull thing? And that twisty thing?

Now that my knowledge of the world has been refined through growing up, I know what they’re for.

Through the same combination of time and education, the cannabis industry has begun to show us the marvels of what terpenes can do as a medicine.¹

But have much more to do in nature than improve our health; they are also protecting the plants in which they exist.

Terpenes deter predators. According to Escalera et al., plants, fungi, and even some animals produce sesquiterpenes that are “potent activators of mammalian peripheral chemosensory neurons, causing pain and neurogenic inflammation”.²In other words, the production of terpenes in nature is used to physically hurt mammals that might otherwise want to chew on the plant producing them.

They not only fight off mammals, but they also repel insects. Pinene, for example, is incredibly powerful at keeping insects away, according to a 2010 study in Bioresource Technology.³

In both cases, against mammals and insects, plants are using terpenes to poison their potential predators. Amazingly, terpenes also can warn other plants that the enemy is near, masticating the very plant unselfishly sending out the distress signal.⁴

Terpenes are diverse. They don’t all hurt and repel. In fact, there are some plants that use terpenes as a way to recruit species for protection. A 2006 report in the Journal of Ecology spoke about the ability of some plants to attract the predators and parasitoids of insects that want to eat them.⁵ As a result, those plants had lower instances of being attacked by insects. Essentially, the plants are chemically recruiting their own bodyguards.

When we select the cannabis that we want, we always go to our smell. The terpenes that interact with our nostrils are an indication of how that cultivar will work for us. However, that same system that lets us know we found a good batch is the same system that can kill insects, fend off large mammals, and even encourage an army of parasitoids to protect plants.

References

1. Cho et al. “Terpenes from Forests and Human Health.” Toxicol Res., 2017, Volume 33(2):97-106. [Journal Impact Factor: 1.89; Times Cited = 20]
2. Escalera et al. “TRPA1 mediates the noxious effects of natural sesquiterpene deterrents.” J Biol Chem., 2008, Volume 283(35):24136-44. [Journal Impact Factor: 4.01; Times Cited = 23]
3. Dutta et al. “Remarkable preservation of terpenoids and record of volatile signalling in plant-animal interactions from Miocene amber.” Sci Rep., 2017, Volume 7(1):10940. [Journal Impact Factor: 4.122; Times Cited = 8]
4. Baldwin, I., et al., “Volatile signaling in plant-plant interactions: ‘talking trees’ in the genomic era”, Science, 2006, Volume 311: 812–815. [Journal Impact Factor: 37.205; Times Cited = 665]
5. Nerio et al. “Repellent activity of essential oils: a review.” Bioresour Technol., 2010, Volume 101(1):372-8. [Journal Impact Factor: 5.807; Times Cited = 61]

Original Article by Terpenes and Testing