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Journal of Botany
Volume 2009, Article ID 842869, 9 pages
http://dx.doi.org/10.1155/2009/842869
Research Article

Nuclei of Taxus baccata: Flavanols Linked to Chromatin Remodeling Factors

1Department für Pflanzenwissenschaften, Technische Universität München (TUM), Wissenschaftszentrum Weihenstephan (WZW), 85354 Freising, Germany
2Department für Biowissenschaftliche Grundlagen, Fachgebiet für Physikalische Biochemie, Technische Universität München (TUM), Wissenschaftszentrum Weihenstephan (WZW), 85354 Freising, Germany

Received 2 March 2009; Revised 9 July 2009; Accepted 14 September 2009

Academic Editor: Jutta Ludwig-Mueller

Copyright © 2009 Walter Feucht et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Microscopic studies of young needles and shoot tips from Taxus baccata showed that flavanols are localized in the nuclei. This observation is based on the histochemical staining of flavanols with the DMACA reagent. The colour that is obtained with this reagent varies from pale to deep blue, depending on the amount of flavanols. This study is focused on nondifferentiated cell lineages and on differentiating cells. The key point to note is that all nuclei of a cell lineage showed a uniform DMACA staining pattern based on the amount and structural appearence of nuclear flavanols. This points to transcriptional and epigenetic programming. However, comparing various cell lineages from different shoot tips and needles revealed a lineage-specific expression of nuclear flavanols. This result implied that both positional and developmental signals from neighbouring cells were involved in the nuclear flavanol binding of lineages. The cells of a developmentally advanced lineage loose their intimate contact and, then, they separate from each other to undergo an autonomous, individual sequence of differentiation. This in turn was accompanied by differences in the nuclear flavanol patterns of the single cells. Investigating different mitotic stages revealed a wide spectrum in flavanol staining intensities of the chromosomes. These observations should be linked to UV-VIS spectroscopical kinetic results indicating that nuclear flavanols bound to histones are involved in epigenetically regulated modification of chromatin. The kinetic studies show that catechin is relatively rapidly degraded by oxygen in the presence of M g 2 + -ions. However, this degradation reaction is strongly inhibited when histone proteins were added. This behaviour is a clear indication that coregulatory interactions exist between catechin and histones.