Journal Article

Auxin-Dependent Cell Cycle Reactivation through Transcriptional Regulation of Arabidopsis E2Fa by Lateral Organ Boundary Proteins

Berckmans, Barbara, Naramoto, Satoshi, Koncz, Csaba, Friml, Jiří, Beeckman, Tom, Magyar, Zoltan, Schmid, Stephan P.C., Parizot, Boris, Vassileva, Valya, Maes, Sara, Bögre, Laszlo, Kamei, Claire Lessa Alvim, De Veylder, Lieven, Persiau, Geert, De Jaeger, Geert, Simon, Rüdiger

2011

Overview

Multicellular organisms depend on cell production, cell fate specification, and correct patterning to shape their adult body. In plants, auxin plays a prominent role in the timely coordination of these different cellular processes. A well-studied example is lateral root initiation, in which auxin triggers founder cell specification and cell cycle activation of xylem polepositioned pericycle cells. Here, we report that the E2Fa transcription factor of Arabidopsis thaliana is an essential component that regulates the asymmetric cell division marking lateral root initiation. Moreover, we demonstrate that E2Fa expression is regulated by the LATERAL ORGAN BOUNDARY DOMAIN 18/LATERAL ORGAN BOUNDARY DOMAIN33 (LBD18/LBD33) dimer that is, in turn, regulated by the auxin signaling pathway. LBD18/LBD33 mediates lateral root organogenesis through E2Fa transcriptional activation, whereas E2Fa expression under control of the LBD18 promoter eliminates the need for LBD18. Besides lateral root initiation, vascular patterning is disrupted in E2Fa knockout plants, similarly as it is affected in auxin signaling and Ibd mutants, indicating that the transcriptional induction of E2Fa through LBDs represents a general mechanism for auxin-dependent cell cycle activation. Our data illustrate how a conserved mechanism driving cell cycle entry has been adapted evolutionarily to connect auxin signaling with control of processes determining plant architecture.

• Publisher: American Society of Plant Biologists
• Subject: Arabidopsis / Arabidopsis - cytology / Arabidopsis - genetics / Arabidopsis - physiology / Arabidopsis Proteins / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Arabidopsis thaliana / Auxins / Cell Cycle / Cell Cycle - physiology / Cell cycle proteins / Cell division / cytology / E2F Transcription Factors / E2F Transcription Factors - genetics / E2F Transcription Factors - metabolism / Gene expression regulation / Gene Expression Regulation, Plant / Gene Expression Regulation, Plant - genetics / Gene Knockout Techniques / Genes / genetics / Indoleacetic Acids / Indoleacetic Acids - metabolism / metabolism / Mutagenesis, Insertional / mutants / Nicotiana - genetics / Nicotiana - metabolism / organogenesis / physiology / plant architecture / Plant cells / Plant Roots / Plant Roots - cytology / Plant Roots - genetics / Plant Roots - physiology / Plant Vascular Bundle / Plant Vascular Bundle - cytology / Plant Vascular Bundle - genetics / Plant Vascular Bundle - physiology / Plants / Plants, Genetically Modified / process control / Promoter Regions, Genetic / Promoter Regions, Genetic - genetics / Root initiation / roots / Signal Transduction / Signal Transduction - physiology / Tobacco / transcription factors / Transcription Factors - genetics / Transcription Factors - metabolism / Transcriptional Activation / xylem