Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-22T20:17:22.610Z Has data issue: false hasContentIssue false

The effect of u.v.-B radiation on u.v.-absorbing secondary metabolites in birch seedlings grown under simulated forest soil conditions

Published online by Cambridge University Press:  01 December 1997

ANU LAVOLA
Affiliation:
Department of Biology, University of Joensuu, P.O. Box 111, SF-80101 Joensuu, Finland
RIITTA JULKUNEN-TIITTO
Affiliation:
Department of Biology, University of Joensuu, P.O. Box 111, SF-80101 Joensuu, Finland
PEDRO APHALO
Affiliation:
Faculty of Forestry, University of Joensuu, P.O. Box 111, SF-80101 Joensuu, Finland
TANIA DE LA ROSA
Affiliation:
Faculty of Forestry, University of Joensuu, P.O. Box 111, SF-80101 Joensuu, Finland
TARJA LEHTO
Affiliation:
Faculty of Forestry, University of Joensuu, P.O. Box 111, SF-80101 Joensuu, Finland
Get access

Abstract

Birch (Betula pendula Roth) seedlings were grown under enhanced u.v.-B radiation and simulated forest-soil conditions, after which individual secondary metabolites were determined in the leaves. It was found that not all of the u.v.-absorbing secondary metabolites of the seedlings responded to supplementary u.v.-B radiation. Under increased u.v.-B radiation, significant increases in concentration were observed only for the major flavonoid, quercitrin, the minor flavonoid, myricetin-3-galactoside, and for chlorogenic acid. On the other hand, 3,4′dihydroxypropiophenone-3-β-D-glucopyranoside decreased under u.v.-B irradiation. The concentration of phenolic compounds in the leaves changed during the growing season (between two harvests) but this change was not related to u.v.-B enhancement. A low availability of mineral nutrients did not impair the capacity of the seedlings to accumulate u.v.-protecting phenolic compounds under increased u.v.-B radiation. The growth conditions used might have affected the intracellular concentrations of secondary metabolites, and thus furnished the birch seedlings with an increased tolerance of u.v.-B radiation. These findings point to the significance of certain phenolic components in the protection of deciduous trees against u.v.-B radiation.

Type
Research Article
Copyright
© Trustees of the New Phytologist 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)