title: Measuring antioxidants in tree species in the natural environment: from sampling to data evaluation.
abstract: Biochemical measurements of antioxidants and protective pigments have been successfully introduced as markers of environmental stress in field studies (mainly forest studies). A guideline for field sampling and analysis methods is required to allow better comparison of data from different studies. The present review paper recommends HPLC methods for the analysis of ascorbate and glutathione (in oxidized and reduced form), tocopherols, and chloroplast pigments. Methodological variations are substantially lower (coefficients of variance of repeated extractions typically 4-9%) than biological variations of field samples (typical variation coefficients 8-36%), hence special emphasis is put on considerations of sampling standardization in the field with respect to sample time (seasonal and diurnal) and representative sampling of individuals and tissues. Following the suggestions in this paper would enable researchers to produce results that could be compared with those of several forest studies on conifers published in recent years. A larger data-set available for multivariate statistical evaluations (e.g. principal component analysis and cluster analysis) will enhance the diagnostic value of such investigations.
authors.affiliation: Institut für Pflanzenphysiologie, University of Graz, Schubertstrasse 51, A-8010 Graz, Austria. michael.tausz@uni-graz.at
authors.forename: Michael
authors.initials: M
authors.lastname: Tausz
authors.forename: Astrid
authors.initials: A
authors.lastname: Wonisch
authors.forename: Dieter
authors.initials: D
authors.lastname: Grill
authors.forename: Domingo
authors.initials: D
authors.lastname: Morales
authors.forename: Maria Soledad
authors.initials: MS
authors.lastname: Jiménez
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D001205:Ascorbic Acid / Q000032:analysis; D015415:Biomarkers; D002338:Carotenoids / Q000032:analysis; D002734:Chlorophyll / Q000032:analysis; D003625:Data Collection; D005978:Glutathione / Q000032:analysis; D010860:Pigments, Biological / Q000032:analysis; D014197:Trees / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D010860:Pigments, Biological; D002734:Chlorophyll; D002338:Carotenoids; D005978:Glutathione; D001205:Ascorbic Acid