The effect of solar UV-B radiation on terpenes and biomass production in Grindelia chiloensis (Asteraceae), a woody perennial of Patagonia, Argentina

ZAVALA, J; RAVETTA, D.A.

PLANT ECOLOGY

SPRINGER

Lugar: Berlin; Año: 2002 vol. 16 p. 185 - 191

1385-0237

Key words: Carbon partitioning, Photobiology, Resin, Terpenes, Ultraviolet-B radiationAbstractUV-B radiation is absorbed effectively by nucleic acids and other sensitive targets, potentially causing harmfulphotochemical effects. Protection against UV-B radiation may be afforded by flavonoids and other phenolics,which absorb strongly in the UV region, but little is known about the role played by other compounds, such asterpenes. Grindelia chiloensis, native of Patagonia (Argentina), can accumulate as much as 25% resin (terpenes)in its leaves. The present investigation was carried out to test the effect of solar UV-B radiation on the allocation ofphotoassimilates to biomass and terpenes. Exposure to UV-B radiation reduced whole plant biomass, plant heightand leaf area, and increased leaf thickness and resin accumulation in Grindelia chiloensis. Higher absorbancewas found for refined resin in the UV-B waveband from plants grown under solar UV-B radiation than plantswithout UV-B radiation. These chemical and structural changes could protect the plant from UV radiation, andmay help elucidate the importance of epicuticular resins for a species as G. chiloensis native to an environmentwith maximum daily integrated values of solar UV-B irradiance.