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Endoreduplication is not inhibited but induced by aphidicolin in cultured cells of tobacco.
- Source :
-
Journal of experimental botany [J Exp Bot] 2002 Apr; Vol. 53 (369), pp. 669-75. - Publication Year :
- 2002
-
Abstract
- Endoreduplication is a common process in plants that allows cells to increase their DNA content. In the tobacco cell cultures studied in this work it can be induced by simple hormone deprivation. Mesophyll protoplast-derived cells cultured in the presence of NAA (auxin) and BAP (cytokinin) keep on dividing, while elongation and concomitant DNA endoreduplication are induced and maintained in a medium containing only NAA. If aphidicolin is given to the two types of culture, no effect is observed on elongating, endoreduplicating cells. However, the cells programmed for division switch to elongation and DNA endoreduplication. Thus aphidicolin, an inhibitor of the replicative DNA polymerases, alpha and delta, does not inhibit endoreduplication, and furthermore actually induces it when the mitotic cell cycle is blocked. DNA duplication and cell growth can only be completely blocked if ddTTP, an inhibitor of DNA polymerase-beta, is given together with aphidicolin. This result implies that an aphidicolin-resistant DNA polymerase, such as the repair-associated DNA polymerase-beta, can mediate DNA synthesis during endoreduplication and can substitute for polymerases-alpha and -delta when the latter are inhibited. Similar results are obtained in cultures of the BY-2 cell line by withdrawing auxins from the culture medium. In this cell line endoreduplication is induced only in a small proportion of the cells. A greater proportion of the cells are blocked in the G(2) phase of the cell cycle.
- Subjects :
- Cells, Cultured
DNA, Plant genetics
DNA, Plant metabolism
DNA-Directed DNA Polymerase drug effects
Drug Interactions
Flow Cytometry
Plant Leaves cytology
Plant Leaves drug effects
Plant Leaves genetics
Protoplasts cytology
Protoplasts drug effects
Thymine Nucleotides pharmacology
Nicotiana cytology
Nicotiana genetics
Aphidicolin pharmacology
Cell Division drug effects
Nicotiana drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0022-0957
- Volume :
- 53
- Issue :
- 369
- Database :
- MEDLINE
- Journal :
- Journal of experimental botany
- Publication Type :
- Academic Journal
- Accession number :
- 11886886
- Full Text :
- https://doi.org/10.1093/jexbot/53.369.669