The Scientific Feat That Birthed the Blue Chrysanthemum

In a world first, scientists engineered the flowers to take on an azure hue

Blue Mums
Blue chrysanthemums Science Advances

Blue may seem like a common color in nature. After all, our brilliant sky is blue. But it turns out, the color blue is pretty hard to come by. Not only are there no insects or animals that produce an actual blue pigment (blue creatures create the color through optical tricks) fewer than 10 percent of the world’s 280,000 flowering plants have blue blossoms, reports Kristen V. Brown at Gizmodo. But that may soon change.

Researchers in Japan inserted two genes into chrysanthemums, creating the first blue blooms of the flower, which more commonly takes on the colors red, orange, yellow, purple or white. As Elizabeth Pennisi at Science reports, the creation of blue flowers involves some pretty complex plant chemistry. Pennisi writes:

"Anthocyanins—pigment molecules in the petals, stem, and fruit—consist of rings that cause a flower to turn red, purple, or blue, depending on what sugars or other groups of atoms are attached. Conditions inside the plant cell also matter. So just transplanting an anthocyanin from a blue flower like a delphinium didn’t really work."

To make chrysanthemums blue, researchers from the National Agriculture and Food Research Organization inserted a gene from the bluish Canterbury bell into red mums. The presence of this gene modified anthocyanin in the mums, producing purplish flowers. To achieve a truer blue, the researchers added a second gene from the butterfly pea into the mix. That did the trick, producing blue-violet mums. They report their results in the journal Science Advances. 

So why make blue mums? As Brown reports, the flower market has a voracious appetite for new colors and blue versions of popular flowers could be a boon the industry. Blue in particular has been a sought-after color. Breeders have found it almost impossible to produce the hue through traditional techniques. In 1840, horticultural societies of Britain and Belgium offered a 500,000-franc reward to anyone who could breed a truly blue rose, a prize that was never claimed. In 2005, researchers finally produced a blue rose through gene editing, Brown writes, which initially sold for ten times the price of normal roses.

It’s likely blue mums will be just as popular. “Chrysanthemums, roses, carnations and lilies are major floricultural plants, [but] they do not have blue flower cultivars,” Naonobu Noda, lead-author of the study tells Brown. He also says similar techniques can be used to make blue versions of other flowers. “None has been able to generate blue flower cultivar by general breeding technique.”

But it’s not just about horticultural novelty. As Rachael Lallensack at Nature reports, learning how to produce blue could lead to new manufacturing methods for the pigments.

Don’t expect blue mums in the garden department anytime soon. As Pennisi reports, before the plants can be commercialized the researchers need to produce a version that cannot reproduce and spread in the environment. Since they are considered genetically modified organisms, the blue flowers may also be banned in parts of Europe and other places with restrictions on GMOs.

Though it technically falls on the blue scale, there is some criticism that the new chrysanthemum sits on the violet or lavender end of the blue spectrum. But don't be blue about it: Noda hopes to achieve an even more azure hue, and to accomplish this there is still more to do. Scientists need a better understanding of the mechanisms that control the color of blue flowers that really makes them pop. Until then, we may need to accept a little purple with our blue.

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