Does ozone stress change the primary or secondary metabolites of birch (<i>Betula pendula</i> Roth.)?

Abstract

SUMMARY In field experiments three clones of two‐year‐old birch (Betula pendula Roth.) were exposed for one growing season to an ozone concentration 1–2 times higher than ambient. At the end of August, leaf and stem material was analyzed for a wide range of primary and secondary metabolites. Although most of these metabolites were not significantly affected by ozone exposure, ozone‐treated leaves contained larger concentrations of total sugars and reduced amounts of the phenolic glucoside, dehydrosalidroside. In the stems, greater amounts of catechin pentoside, hyperoside and papyriferic acid were found. The results indicated considerable inter‐ and intra‐clonal variation in the production of phytochemicals in both leaves and stems.