ENHANCED UV-B RADIATION MAY LEAD TO THE DECREASE OF SPECIFIC PHENOLIC COMPOUNDS IN NORWAY SPRUCE NEEDLES

摘要

The long-term (23 weeks) exposure of Norway spruce needles to supplemental (+25%) ultraviolet-B (UV-B) ir-radiances at field conditions resulted in the slight increase , of catechin (ca 7%; p >0.05); however, significant decreases of extracted 4-hydroxyacetophenone (ca 80%; p <0.01) and picein (ca 72%; p <0.01). These findings document the differences in synthesis of specific phenolic compounds induced by UV-B radiation. The possible relations to plant tolerance are discussed.