Scientists Figure Out Why Roses Don't Smell as Good as They Used To

Roses are red, violets are blue, but they just don't smell like they used to.

A team of 40 international researchers has successfully mapped an heirloom rose's genome and learned where the bud's color and scent come from—and how to tweak those traits to yield a more fragrant flower. Historically, rose breeders have opted for pretty petals over pleasant perfumes, and as a result, the rose's natural scent has faded over time, according to Science News.

The study, published in the journal Nature Genetics, reports that some of the genes of the "Old Blush" pink China rose cancel each other out, "with some turning on to brew a scent component while others shut down manufacture of anthocyanin pigments needed for rosy petals," Science News reports. The researchers also found 22 new biochemical steps in the production of terpenes, the volatile organic compounds key to the rose's perfume. With a better understanding of the complex relationship between color and scent, breeders of both roses and other plants could start producing flowers without sacrificing one trait for the other.

"The big challenge is you need to know what to edit," Todd Mockler, a plant researcher who was not involved with the rose study, tells The New York Times. “You can't just randomly start editing. You have to know what to target. The only way to know that is to have a genome sequence.”

The rose is most closely related to the strawberry plant, but it also has family ties with the apple and pear. Given that modern roses contain a blend of genes from between eight and 20 different species, mapping its genome was no small feat. It took researchers eight years to complete this study, according to the BBC. And while it's not the first time the rose genome has been mapped, this new analysis is far more comprehensive.

Similarly, the sunflower contains a complex genetic code, but scientists were able to map its genome last year, serving to aid future researchers and flower breeders. 

[h/t BBC]