TISSUE LOCALIZATION OF PHENOLIC-COMPOUNDS IN PLANTS BY CONFOCAL LASER-SCANNING MICROSCOPY

Phenolic compounds are involved in many interactions of plants with th eir biotic and abiotic environment. These substances accumulate in dif ferent plant tissues and cells during ontogenesis and under the influe nce of various environmental stimuli, respectively. Studies on the tis sue localization of phenolic compounds provide a fundamental prerequis ite for understanding the ecological functions of these compounds. The present work shows the localization of various phenolics in cell wall s, vacuoles, and associated with cell nuclei, in leaves of a monocotyl edonous and a dicotyledonous plant, in a gymnosperm as well as in rhiz omes of a horsetail by confocal laser scanning microscopy (CLSM). Usin g fresh plant material, it compares in detail the tissue localization of autofluorescent styrylpyrones and hydroxycinnamic acids and the vis ualization of epidermal flavonoid compounds using shift reagents like ammonia, and fluorescence-inducing reagents like Naturstoffreagenz A ( diphenylboric acid 2-aminoethyl ester). The comparison of microscopic data obtained from different plant species shows the advantages and li mitations of confocal laser scanning microscopy in ecological biochemi stry of phenolic plant metabolites.