Scientists at The Hebrew University of Jerusalem have unlocked the secret behind petunia’s captivating scent—tracing it back to a single gene, PhDEF. This gene not only shapes the flower’s petals but also triggers the production of alluring fragrances that attract pollinators. The discovery could revolutionize the fragrance industry and horticulture, offering new ways to enhance floral scents without altering a flower’s natural beauty.

[Hebrew University of Jerusalem]– A study led by Prof. Alexander Vainstein from The Robert H. Smith Faculty of Agriculture, Food and Environment at The Hebrew University of Jerusalem has revealed the crucial role of the PhDEF gene in regulating floral scent production in petunia flowers. This discovery sheds new light on how plants develop key traits to attract pollinators, with potential implications for agriculture, horticulture, and biotechnology.

The study, published in The Plant Cell, highlights how PhDEF, a homeotic gene known for its role in petal formation, also plays an essential role in activating scent production at later stages of flower development. Using advanced genetic analysis and viral-induced gene silencing , the research team demonstrated that suppressing PhDEF significantly reduced volatile emissions, thereby weakening the floral scent.

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

The study identified PhDEF as a key activator of EOBI and EOBII, two major transcriptional regulators of floral scent production, along with other biosynthetic genes responsible for the emission of volatile compounds. By activating these pathways, PhDEF ensures the release of phenylpropanoid-based volatiles that make flowers more attractive to pollinators.

Suppressing PhDEF led to a notable decline in the production of essential scent compounds, including methyl benzoate and benzyl alcohol. Despite this reduction, the study found that PhDEF suppression did not alter petal morphology, indicating that scent production can be genetically manipulated without affecting flower structure.

The findings open new possibilities for enhancing floral scent in commercial flower varieties or modifying scent profiles for agricultural crops that rely on pollination. Additionally, understanding PhDEF’s regulatory functions could contribute to bioengineering efforts to optimize scent production in flowers, with applications in both horticulture and the fragrance industry.

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