The Arabidopsis D-Type Cyclin CYCD2;1 and the Inhibitor ICK2/KRP2 Modulate Auxin-Induced Lateral Root Formation
| Autor: | Celine Forzani, Luis Sanz, Mark Estelle, Sarah M. de Jager, James A. H. Murray, Farah Patell, Hong Wang, Hong Ren, Jeroen Nieuwland, Walter Dewitte, Aurélio Campilho, Bo Wen, Pedro Quelhas, Craig Titmus |
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| Rok vydání: | 2011 |
| Předmět: |
0106 biological sciences
Proteasome Endopeptidase Complex Arabidopsis Cell Cycle Proteins Plant Science Plant Roots 01 natural sciences 03 medical and health sciences Gene Expression Regulation Plant Auxin Cyclin-dependent kinase Cyclins Kinase activity Lateral root formation Research Articles 030304 developmental biology Cell Nucleus chemistry.chemical_classification 0303 health sciences Indoleacetic Acids biology Arabidopsis Proteins Cell Cycle Lateral root food and beverages Cell Biology Meristem biology.organism_classification Cell biology Pericycle chemistry Mutation biology.protein 010606 plant biology & botany |
| Zdroj: | The Plant Cell. 23:641-660 |
| ISSN: | 1532-298X 1040-4651 |
| DOI: | 10.1105/tpc.110.080002 |
| Popis: | The integration of cell division in root growth and development requires mediation of developmental and physiological signals through regulation of cyclin-dependent kinase activity. Cells within the pericycle form de novo lateral root meristems, and D-type cyclins (CYCD), as regulators of the G₁-to-S phase cell cycle transition, are anticipated to play a role. Here, we show that the D-type cyclin protein CYCD2;1 is nuclear in Arabidopsis thaliana root cells, with the highest concentration in apical and lateral meristems. Loss of CYCD2;1 has a marginal effect on unstimulated lateral root density, but CYCD2;1 is rate-limiting for the response to low levels of exogenous auxin. However, while CYCD2;1 expression requires sucrose, it does not respond to auxin. The protein Inhibitor-Interactor of CDK/Kip Related Protein2 (ICK2/KRP2), which interacts with CYCD2;1, inhibits lateral root formation, and ick2/krp2 mutants show increased lateral root density. ICK2/KRP2 can modulate the nuclear levels of CYCD2;1, and since auxin reduces ICK2/KRP2 protein levels, it affects both activity and cellular distribution of CYCD2;1. Hence, as ICK2/KRP2 levels decrease, the increase in lateral root density depends on CYCD2;1, irrespective of ICK2/CYCD2;1 nuclear localization. We propose that ICK2/KRP2 restrains root ramification by maintaining CYCD2;1 inactive and that this modulates pericycle responses to auxin fluctuations. |
| Databáze: | OpenAIRE |
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