The associations of cyclins with highly conserved cyclin-dependent kinases are key events in the regulation of cell cycle progression. The spatio-temporal expression of an Arabidopsis thaliana (L.) Heynh. mitotic cyclin, Arath;CycA2;1, was studied by histochemical β-glucuronidase (GUS) analysis and in-situ hybridizations. The CycA2;1 promoter was active in the egg apparatus before fertilization. During embryogenesis, CycA2;1:gus expression was found in the embryo and the developing endosperm. Throughout plant development, CycA2;1 transcripts were found in both dividing and non-dividing cells, indicating that the expression of this cyclin is not a limiting factor for cell division. In the pericycle and stelar parenchyma, CycA2;1 transcripts were located at the xylem poles, a position that can be correlated with competence for lateral root formation. In addition, CycA2;1:gus expression was upregulated in roots by auxins and in the shoot apex by cytokinins. Transcription of CycA2;1 was shown by reverse transcription polymerase chain reaction to be strongly induced by sucrose in A. thaliana cell suspensions.
|Number of pages||9|
|State||Published - 2000|
Bibliographical noteFunding Information:
The authors thank Martine De Cock for help in preparing the manuscript and Karel Spruyt and Rebecca Verbanck for figures and photographs. This work was supported by grants from the Interuniversity Poles of Attraction Programme (Belgian State, Prime Minister's OOce – Federal OOce for Scientific, Technical and Cultural Affairs; P4/15) and the European Community (FAIR5-CT97-3711 and ERB-BIO4-CT96-0217).
- Arabidopsis (cell cycle)
- Cell cycle
- Gene expression (cyclin)