Cracking the Rose Code: Scientists Discover Why Roses Aren’t Naturally Yellow or Blue

The Curious Case of Rose Colors

Image by László from Pixabay

Roses have long enchanted humanity with their beauty, fragrance, and symbolic meanings. But there’s always been a puzzle: while roses bloom in glorious reds, pinks, and whites, naturally occurring yellow and blue roses are absent. Now, researchers from Tokyo University of Science have discovered the reason behind this colorful limitation—and it all comes down to genetics.

Their findings were published in the journal Scientific Reports.

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Inside the Petal: The Chemistry of Color

Most rose colors are created by a group of pigments called anthocyanins—specifically cyanidin and pelargonidin. These produce red, pink, and purple hues depending on their concentration and the pH of the plant cells.

But when scientists tried to uncover the secret behind yellow and blue roses, they ran into a roadblock.

“We found that key genes required for producing delphinidin—the pigment responsible for blue hues—and chalcone 2’glucosyltransferase, important for stabilizing yellow pigments, are either missing or inactive in roses,” explained lead researcher Dr. Yoshikazu Tanaka.

Genome sequencing of 205 samples representing 84 species reveal evolutionary and geographical history of the Rosa genus. Credit: Nature Plants (2025). DOI: 10.1038/s41477-025-01955-5

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The Missing Genes

The team conducted a comprehensive genetic analysis across several rose varieties, including hybrid cultivars and wild species. They focused on genes linked to the flavonoid biosynthesis pathway—the route by which plants produce colored pigments.

They discovered that while red and pink colors are produced through active genes, the genes required to create delphinidin (blue pigment) and certain stabilizing enzymes for yellow hues are non-functional or absent in modern roses.

This means that the genetic “paint palette” of roses is incomplete—lacking the tools to naturally produce yellow or blue hues without human intervention.

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Engineering the Impossible?

The discovery doesn’t just solve a botanical mystery—it opens doors for the future of floral engineering.

In recent years, researchers have already tried to create blue roses using genetic modification techniques, such as introducing pansy or petunia genes into roses. But now, with this more detailed map of which genes are missing, scientists could use CRISPR gene editing to reintroduce or activate the right pathways.

“This study provides critical information for future breeding of novel rose colors using modern biotechnology,” said Dr. Tanaka.

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Why This Matters Beyond Roses

While this breakthrough is exciting for rose lovers and breeders, it also has broader implications. Understanding how flower colors evolve and which genes are essential can help botanists:

• Conserve wild flower species
• Adapt plants for changing climates
• Improve pollination success by attracting specific pollinators
• Boost plant-based dye production for sustainable industries

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🌟 A Blooming Future Awaits

Now that scientists know why roses can’t naturally wear yellow or blue, the question isn’t if we’ll see more colorful roses—it’s how soon. With gene editing and modern breeding tools, the future of floral diversity is wide open.

🌼 Could the next Valentine’s Day bouquet feature a sky-blue rose?
Stay curious—nature’s palette is more flexible than we ever imagined.