title: Phenolic biosynthesis, leaf damage, and insect herbivory in birch (Betula pendula).
abstract: The effect of both caterpillar herbivory and artificial damage on phenylalanine ammonia lysase (PAL) activity of birch foliage was measured, using an intact cell assay. After artificial damage there was a small increase in PAL activity in damaged leaves but no change in adjacent undamaged ones. Insect grazing produced a larger increase in PAL activity, and the enzyme activity was also increased in adjacent undamaged leaves. Artificial damage increased the phenolic levels of the damaged leaves. Insect grazing caused a larger, longer-lasting increase in phenolic levels and also elevated phenolic levels in undamaged leaves. The possible role of these wound-induced biochemical changes in birch is discussed.
authors.affiliation: Department of Biology, University of York, Heslington, Y01 5DD, York, England.
authors.forename: S E
authors.initials: SE
authors.lastname: Hartley
authors.forename: R D
authors.initials: RD
authors.lastname: Firn