Phenolics and Compartmentalization in the Sapwood of Broad-Leaved Trees

Tree survival depends on the chemistry of phenolic compounds, a broad class of chemicals characterized by a hydroxylated benzene ring. In trees, phenolics occur frequently as polymers, acids, or glycosylated esters 1 and perform diverse functions. For example, lignin, a phenylpropane heteropolymer, provides structural strength to wood.2 The induced production of phenols is a common response to injury and infection for both woody and nonwoody plants.3·4 Phenolics also deter herbivores from feeding on leaves,5 slow the spread of pathogens in roots and bark,6 confer some measure of durability to heartwood/ and with other secondary metabolites, tend to limit the spread of infection in the sapwood of conifers~·9 and broad-leaved trees. 10·11 This report focuses on methods to detect, measure, and identify phenolics as markers of the response of sapwood to wounding and infection in broad-leaved trees.