Floral Scent Diversity is Differently Expressed in Emitted and Endogenous Components in Petunia axillaris Lines

Abstract

• Background and Aims Among the subspecies of Petunia axillaris are various lines emitting sensorially different scents. Analysis of variations in floral scent among genetically close individuals is a powerful approach to understanding the mechanisms for generating scent diversity.• Methods Emitted and endogenous components were analysed independently to gain information about evaporation and endogenous production in 13 wild lines of P. axillaris. A dynamic headspace method was used to collect emitted components. Endogenous components were extracted with solvent. Both of these sample types were subjected to quantitative and qualitative analysis by gas chromatography (GC)–flame ionization detector (FID) and GC–mass spectrometry (MS).• Key Results and Conclusions Whereas the profiles of emitted compounds showed qualitative homogeneity, being mainly composed of methyl benzoate with quantitative variation, the profiles of endogenous compounds showed both qualitative and quantitative variation. A negative correlation was found between the evaporation ratio and boiling point of each compound examined. Lower boiling point compounds were strongly represented in the emitted component, resulting in the reduction of qualitative variation in floral scent. In conclusion, floral scent diversity results from variation in both the endogenous production and the evaporation rate of the individual volatile compounds.

Circadian clock gene LATE ELONGATED HYPOCOTYL directly regulates the timing of floral scent emission in Petunia

“…S5) revealed that the temporal availability of endogenous compounds mirror the external emission levels of those same compounds. These findings support previous evidence that emission of floral volatiles is simply based on diffusion, and regulated primarily at the synthesis level (31,32).…”

A comparative analysis of characteristic floral scent compounds in Prunus mume and related species

“…29,30) Quantitative analysis of the endogenous extracts and the headspace volatiles of different plant species indicated that only a small amount of compounds was emitted from the flower in 1 h and most of the compounds remained in the floral tissue. This observation suggests that the emission of stored volatile compounds from floral tissues may be controlled, perhaps by an excretory process regulated at the cellular level.…”

Effect of Temperature on the Floral Scent Emission and Endogenous Volatile Profile ofPetunia axillaris

“…The emitted volatile compounds were collected for one hour (23:00-24:00) from 1-day-old flowers by the headspace method. 7) Flowers were covered with Tedlar bags (500 ml in volume; GL Science, Tokyo, Japan). A constant stream of air (approximately 500 ml/min) filtered through activated charcoal was piped through the bag, and the volatile compounds were collected in traps of Tenax-TA (60/80 mesh, 150 mg; GL Science).…”

“…After ethyl decanoate (20 mg) had been added as an internal standard, the extract was dried over anhydrous sodium sulfate and concentrated at 40 C in a water bath. 7) Preparation of the endogenous volatiles for analysis. The flowers were harvested at 24:00 after collecting the emitted volatile compounds, and the flower tissues without the calyx were frozen in liquid nitrogen and ground in a mortar.…”

“…8) The extract was dehydrated with anhydrous sodium sulfate and concentrated at 40 C in a water bath. 7) GC-MS and GC analyses. Capillary gas chromatography-mass spectrometry (GC-MS) was performed with on Agilent 6890N gas chromatograph coupled to an Agilent 5973N mass selective detector (Agilent Technologies, Wilmington, DE, USA).…”