Deoxyuridine triphosphatase expression defines the transition from dormant to sprouting potato tuber buds
Identification of molecular markers defining the end of tuber dormancy prior to visible sprouting is of agronomic interest for potato growers and the potato processing industry. In potato tubers, breakage of dormancy is associated with the reactivation of meristem function. In dormant meristems, cells are arrested in the G1/G0 phase of the cell cycle and re-entry into the G1 phase followed by DNA replication during the S phase enables bud outgrowth. Deoxyuridine triphosphatase (dUTPase) is essential for DNA replication and was therefore tested as a potential marker for meristem reactivation in tuber buds. The corresponding cDNA clone was isolated from potato by PCR. The deduced amino acid sequence showed 94% similarity to the tomato homologue. By employing different potato cultivars, a positive correlation between dUTPase expression and onset of tuber sprouting could be confirmed. Moreover, gene expression analysis of tuber buds during storage time revealed an up-regulation of the dUTPase 1 week before visible sprouting occurred. Further analysis using an in vitro sprout assay supported the assumption that dUTPase is a good molecular marker to define the transition from dormant to active potato tuber meristems.
KeywordsSolanum tuberosum Potato Tuber dormancy Tuber sprouting Meristem reactivation DNA replication dUTPase
The authors want to thank Stephen Reid for excellent technical assistance and Christine Hösl for taking care of the plants in the greenhouse. The project was funded by EU-SOL (FOOD-CT-2006-016214).
- Burton WG (1989) Dormancy and sprout growth, 3rd edn. The Potato, Longman Scientific and Technical, Essex, UK, pp 470–504Google Scholar
- Hemberg T (1985) Potato rest. In: Li PH (ed) Potato physiology. Academic Press, Orlando, FL. ISBN 0-12-447660-0, 353-388Google Scholar
- Kloosterman B, De Koeyer D, Griffiths R, Flinn B, Steuernagel B, Scholz U, Sonnewald S, Sonnewald U, Bryan GJ, Prat S, Banfalvi Z, Hammond JP, Geigenberger P, Nielsen KL, Visser RG, Bachem CW (2008) Genes driving potato tuber initiation and growth: identification based on transcriptional changes using the POCI array. Funct Integr Genomics 8:329–340CrossRefPubMedGoogle Scholar
- Suttle JC (1996) Dormancy in tuberous organs: problems and Perspectives. In: Lang GA (ed) Plant dormancy: physiology, biochemistry and molecular biology. CAB International, Wallingford, UK, pp 133–143Google Scholar
- Va’t Hof J (1973) The regulation of cell division in higher plants. Brookhaven Symp Biol 25:252–265Google Scholar