The Arabidopsis D-Type Cyclin CYCD2;1 and the Inhibitor ICK2/KRP2 Modulate Auxin-Induced Lateral Root Formation

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Luis Sanz (Author) Other; Walter Dewitte (Author) Other; Celine Forzani (Author) Other; Farah Patell (Author) Other; Jeroen Niewland (Author) Other; Bo Wen (Author) Other; Pedro Quelhas (Author) FEUP; Sarah de Jager (Author) Other; Aurélio Campilho (Author) FEUP; Hong Ren (Author) Other; Mark Estelle (Author) Other; Hong Wang (Author) Other; James Murray (Author) Other

Journal

Title: Plant Cell

Vol. 23 No. 2

Pages: 641-660

ISSN: 1040-4651

Publisher: American Society of Plant Biologists

Indexing

ISI Web of Knowledge - 44 Citations

ISI Web of Science

Scopus - 52 Citations

Other information

Authenticus ID: P-002-VQ0

DOI: 10.1105/tpc.110.080002

Abstract (EN): 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 G(1)-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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 20