Flowers get their shape and scent from a single gene

Flowers do more than brighten gardens and decorate tables. Their scent – sweet, musky, or sometimes citrusy – isn’t just for human enjoyment. It’s a luring message, a chemical whisper meant for pollinators.

For years, scientists have tried to crack the genetic code behind floral fragrance, and now, a research team has found a crucial piece of the puzzle.

Led by Professor Alexander Vainstein at The Hebrew University of Jerusalem, the study reveals that a single gene, PhDEF, pulls double duty. It doesn’t just shape the petals; it also controls the flower’s scent.

This discovery could reshape agriculture, horticulture, and even biotechnology.

Linking petal shape and scent in flowers

The study flips the script on what we thought PhDEF did. This gene was always known for defining petal identity, but researchers discovered another, unexpected function – it helps flowers produce scent.

And not just at any time. PhDEF kicks in later in flower development, orchestrating the release of compounds that attract pollinators.

Using genetic analysis and viral-induced gene silencing, the research team tested what would happen if PhDEF was turned off.

The result? A dramatic drop in floral fragrance. Petunias that once filled the air with their scent suddenly became undetectable, their chemical signals lost.

“Our findings show that PhDEF is not just responsible for defining petal identity but also for coordinating the production of scent compounds critical for pollination,” said Professor Vainstein.

“This dual functionality suggests that petunia flowers have evolved an integrated regulatory mechanism to optimize their attraction to pollinators.”

Scent production in flowers

PhDEF does not act alone in controlling floral scent. The experts identified it as a key regulator that activates two other important genetic regulators, EOBI and EOBII. These regulators then control a set of genes responsible for producing and releasing floral scent compounds.

Think of PhDEF as a master switch. When it is active, it triggers a chain reaction. First, it turns on EOBI and EOBII, which then activate other genes involved in scent production. This process leads to the creation and emission of molecules like methyl benzoate and benzyl alcohol – compounds that give flowers their characteristic fragrance.

To test PhDEF’s role, the scientists silenced it in petunias. The result was striking: the flowers lost most of their scent, but their petal shape remained unchanged. This proved that scent production and petal formation, though both controlled by PhDEF, are separate processes.

The discovery suggests that floral fragrance can be modified through genetic changes without altering the flower’s physical appearance.

What this means for flowers and crops

Imagine flowers bred for beauty but stripped of their fragrance, such as roses that look stunning but smell like nothing.

Many commercial varieties have suffered this fate. But now, with PhDEF in the spotlight, scientists might be able to bring scent back to flowers bred for aesthetics.

The implications extend beyond ornamental plants. Many crops depend on pollinators, and enhancing floral scent could increase their attractiveness to bees and other essential pollinators. Stronger scents might mean better yields, more reliable pollination, and greater stability for agriculture.

The fragrance industry, too, could benefit. By tweaking PhDEF and its related pathways, bioengineers could craft flowers with specific scent profiles, creating natural perfumes tailored to human preferences.

Nature’s fine-tuned balance

This discovery adds another layer to our understanding of plant biology. It shows how nature optimizes every detail, ensuring that flowers not only look appealing but also produce the right chemical signals at the right time.

The genetic link between petal formation and scent production reveals a carefully balanced system – one that could have applications far beyond what we see today.

“This discovery advances our knowledge of plant biology and offers potential applications for breeding more resilient and pollinator-friendly crops,” said Professor Vainstein.

Science continues to pull back the curtain on nature’s secrets. With every breakthrough, we move closer to harnessing these intricate systems – whether to create more fragrant flowers, improve pollination, or develop new scents for industry.

The more we learn, the more we realize that nothing in nature is accidental. It’s all part of a finely tuned symphony, playing out in every garden, field, and greenhouse.

The study is published in the journal The Plant Cell.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–