Ülo has had a quite a collaboration with Spanish ecophysiologists and that has yielded another publication. This time together with the Josep Peñuelas group in Barcelona, which hides behind an acronym: CREAF-CEAB-CSIC-UAB, CSIC. Not bad!
The authors are: Gerard Farré‐Armengol, Iolanda Filella, Joan Llusià, Ülo Niinemets and Josep Peñuelas; and Functional Plant Biology has accepted their paper called “Optimum temperature for floral terpene emissions tracks the mean temperature of the flowering season” (link). It seems to be kind of a follow-up on last year´s publication by the same authors on the smell of Mediterranean flowers and how climate change will affect this in Global Change Biology (link to full text).
Emissions of volatiles from leaves exhibit temperature dependence with maximums, but optimum temperatures for the release of floral volatiles or the mechanism of optimization of these emissions have not been determined. We hypothesized that flowers have an optimum temperature for the emission of volatiles and, because the period of flowering varies highly among species, that this optimum is adapted to the temperatures prevailing during flowering. To test these hypotheses, we characterized the temperature responses of floral terpene emissions of diverse widespread Mediterranean plant species flowering in different seasons by using dynamic headspace sampling and analysis with gas chromatography mass spectrometry. The floral emissions of terpenes across species exhibited maximums at the temperatures corresponding to the season of flowering, with the lowest optimal temperatures observed in winter-flowering and the highest in summer-flowering species. These trends were valid for emissions of both total terpenes and the various terpene compounds. The results show that the optimum temperature of floral volatile emissions scales with temperature at flowering and suggest that this scaling is the outcome of physiological adaptations of the biosynthetic and/or emission mechanisms of flowers.