EFFECTS OF OZONE AND UV-B RADIATION ON SCOTS PINE.

Most of the experiments investigating the effects of UV-B on plants in closed chambers were performed with artificial radiation differing substantially from that of the solar spectrum.
A new sunlight simulator developed at the GSF allowed us to simulate global radiation with a mean spectral deviation of not more than 16%.

Scots pine seedlings reacted within 72 hours of UV-B irradiation by accumulating four methanol-extractable flavonoids.
The main induced metabolite was identified to be 3",6"-di-O-(4-coumaroyl)-isoquercitrin.
It was shown that this flavonoid was retained, up to 50%. in enzymatically isolated epidermal cell layers.

Ozone has earlier been shown to affect other pathways of secondary metabolism in the needles leading to the accumulation of the stilbenes. pinosylvin and pinosylvin 3-methylether, the flavan catechin. as well as to the induction of the pertinent biosynthetic enzymes.

Season-dependent effects of ozone (ambient and twice ambient) and of two light regimes (high/low UV-B radiation) on secondary metabolism of four-year-old Scots pine saplings were recently investigated in the GSF-Phytotron under meterological conditions simulated according to values measured in 1990 at the Wank, an alpine mountain near Garmisch-Partenkirchen (FRG). Preliminary results of this experiment are presented.

International Symposium on Natural Phenols in Plant Resistance

J.P. SCHNITZLER, T.P. JUNGBLUT, W. HELLER, C. LANGEBARTELS, M. KÖFFERLEIN, H. SANDERMANN Jr

UV-B radiation, tropospheric ozone, Scots pine, flavonoids, stillbenes

https://doi.org/10.17660/ActaHortic.1994.381.59