Eintrag weiter verarbeiten
Arabidopsis CYCD3 D-type cyclins link cell proliferation and endocycles and are rate-limiting for cytokinin responses
Gespeichert in:
Zeitschriftentitel: | Proceedings of the National Academy of Sciences |
---|---|
Personen und Körperschaften: | , , , , , , , , , , |
In: | Proceedings of the National Academy of Sciences, 104, 2007, 36, S. 14537-14542 |
Format: | E-Article |
Sprache: | Englisch |
veröffentlicht: |
Proceedings of the National Academy of Sciences
|
Schlagwörter: |
Zusammenfassung: | <jats:p> Current understanding of the integration of cell division and expansion in the development of plant lateral organs such as leaves is limited. Cell number is established during a mitotic phase, and subsequent growth into a mature organ relies primarily on cell expansion accompanied by endocycles. Here we show that the three <jats:italic>Arabidopsis</jats:italic> cyclin D3 ( <jats:italic>CYCD3</jats:italic> ) genes are expressed in overlapping but distinct patterns in developing lateral organs and the shoot meristem. Triple loss-of-function mutants show that <jats:italic>CYCD3</jats:italic> function is essential neither for the mitotic cell cycle nor for morphogenesis. Rather, analysis of mutant and reciprocal overexpression phenotypes shows that <jats:italic>CYCD3</jats:italic> function contributes to the control of cell number in developing leaves by regulating the duration of the mitotic phase and timing of the transition to endocycles. Petals, which normally do not endoreduplicate, respond to loss of <jats:italic>CYCD3</jats:italic> function with larger cells that initiate endocycles. The phytohormone cytokinin regulates cell division in the shoot meristem and developing leaves and induces <jats:italic>CYCD3</jats:italic> expression. Loss of <jats:italic>CYCD3</jats:italic> impairs shoot meristem function and leads to reduced cytokinin responses, including the inability to initiate shoots on callus, without affecting endogenous cytokinin levels. We conclude that <jats:italic>CYCD3</jats:italic> activity is important for determining cell number in developing lateral organs and the relative contribution of the alternative processes of cell production and cell expansion to overall organ growth, as well as mediating cytokinin effects in apical growth and development. </jats:p> |
---|---|
Umfang: | 14537-14542 |
ISSN: |
0027-8424
1091-6490 |
DOI: | 10.1073/pnas.0704166104 |