Effects of light on terpene hydrocarbon synthesis in Pinus pinaster

Abstract

The biosynthesis of terpene hydrocarbons has been investigated in maritime pine (Pinus pinaster Ait.) seedling primary leaves under light and darkness and with different precursors. Impossible in darkness, the synthesis of monoterpenes (mainly α‐ and β‐pinene) is strongly activated by light. Only 14C‐carbonate and 14C‐acetate can be incorporated into monoterpenes. Activation by light is comparatively much more effective for seedling leaves previously cultivated under short days than in leaves from seedlings given long days. The spectral bands which are efficient for the synthesis of monoterpenes are located around 480 and 685 nm with 14C‐carbonate and 480 and 630 nm with l‐14C‐acetate. Furthermore, this light activation does not occur if leaf pieces instead of whole leaves are used for the incorporation experiments. When 2‐14C‐mevalonic acid and 1‐14C‐isopentenyl pyrosphosphate are applied as precursors, no radioactivity is recorded in monoterpene hydrocarbons even after light exposures. In contrast, sesquiterpene hydrocarbons (caryophyllene and humulene) are easily synthesized under light or darkness in intact or fragmented leaves from the different precursors of photosynthetic or exogenous origin. From these results the compartmentalization in the synthesis of C10 and C15 hydrocarbons appears clear. There is a metabolic cooperation between the photosynthetic tissues and the specific site of elaboration of C10 hydrocarbons, which site is located in the parts where the epithelial cells of resin ducts are functional. The synthesis of sesquiterpene hydrocarbons takes place in the whole leaf without activation by light.

Temperature and Photoperiod Influence Trichome Density and Sesquiterpene Content of Lycopersicon hirsutum f. hirsutum

“…Higher light intensity and duration usually promote terpene accumulation (8,16), and cool nights have been found to increase monoterpene concentration in peppermint (Mentha piperita L.) before flowering (12). Monoterpene concentrations are generally higher in young leaves and peak at or before flowering (3,12), with increased rates of catabolism at the time of flowering (4,5).…”

Induced oleoresin biosynthesis in grand fir as a defense against bark beetles.

“…Thus, reduction in the supply of carbohydrate from source tissues attenuated both constitutive oleoresinosis and the response to stem wounding. The effects of light on the accumulation of oleoresin have been observed previously (49,50); however, the influence of light deprivation on terpene biosynthetic enzymes per se had not (48).…”

Canopy level emissions of 2-methyl-3-buten-2-ol, monoterpenes, and sesquiterpenes from an experimental Pinus taeda plantation

“…Daly and Geron (in preparation) found no farnesenes in P. taeda needle extracts from this site, suggesting that these SQT compounds do not accumulate in glands or storage structures as do β-caryophyllene and α-humulene. Gleizes et al (1980) found that β-caryophyllene and α-humulene could be synthesized in dark or illumination from the photosynthetic metabolite geranyl pyrophosphate and can be stored in resin ducts or glands. Conversely, the farnesenes are known to be produced from the precursor farnesyl pyrophosphate by farnesene synthase activity and emitted de novo, often in response to disturbance such as insect attack (Scutareanu et al, 1996).…”