Leaf carotenoid concentrations and monoterpene emission capacity under acclimation of the light reactions of photosynthesis

Factors controlling the seasonal dynamics in leaf monoterpene emission capacity are not yet well understood. In particular, temperature and light algorithms alone cannot explain the pattern of volatile organic compound (VOC) emissions during spring recovery of photosynthesis in boreal forests, suggesting further physiological controls. Higher isoprenoids, such as carotenoids, and VOCs share the initial steps of their synthesis pathways. Therefore, it could be expected that the pool size of leaf carotenoids and its acclimation interact with leaf monoterpene emission capacity. We examine this interaction in evergreen foliage using the non-storing Quercus ilex as a model species. We modified the light environment of a number of potted trees in order to induce acclimation in leaf carotenoids, and studied the effect on monoterpene emission capacity. The results indicate that monoterpene emission capacity and photosynthetic pigment metabolism are coupled in Q. ilex seedlings growing at or acclimating to different light levels. © 2009.