Diurnal regulation of scent emission in rose flowers

Keren Hendel-Rahmanim, Tania Masci, Alexander Vainstein, David Weiss*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

80 Scopus citations


Previous studies have shown diurnal oscillation of scent emission in rose flowers with a peak during the day (Helsper in Planta 207:88-95, 1998; Picone in Planta 219:468-478, 2004). Here, we studied the regulation of scent production and emission in Rosa hybrida cv. Fragrant Cloud during the daily cycle and focused on two terpenoid compounds, germacrene D and geranyl acetate, whose biosynthetic genes have been characterized by us previously. The emission of geranyl acetate oscillated during the daily light/dark cycle with a peak early in the light period. A similar daily fluctuation was found in the endogenous level of this compound and in the expression of its biosynthetic gene, alcohol acetyl transferase (RhAAT). The rhythmic expression of RhAAT continued under conditions of constant light or darkness, indicating regulation by the endogenous circadian clock. However, the accumulation and emission of geranyl acetate ceased under continuous light. Our results suggest that geranyl acetate production is limited by the level of its substrate geraniol, which is suppressed under constant light conditions. The emission of germacrene D also oscillated during the daily cycle with a peak early in the light period. However, the endogenous level of this compound and the expression of its biosynthetic gene germacrene D synthase (RhGDS) were constant throughout the day. The diurnal oscillation of germacrene D emission ceased under continuous light, suggesting direct regulation by light. Our results demonstrate the complexity of the diurnal regulation of scent emission: although the daily emission of most scent compounds is synchronized, various independently evolved mechanisms control the production, accumulation and release of different volatiles.

Original languageAmerican English
Pages (from-to)1491-1499
Number of pages9
Issue number6
StatePublished - Nov 2007

Bibliographical note

Funding Information:
Acknowledgments This work was supported by the US Israel Binational Agriculture Research and Development fund (grant no. US-3437) and by the Pearlstein Fund for research in Xoriculture at the Hebrew University. We thank the donors for their help.


  • Circadian rhythm
  • Floral scent
  • Geranyl acetate
  • Germacrene D
  • Rose


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