Ring the BELL and tie the KNOX: roles for TALEs in gynoecium development

Nicolas Arnaud,Vã©Ronique Pautot

doi:10.3389/fpls.2014.00093

Nicolas Arnaud, Vã©Ronique Pautot

Open Access

https://doi.org/10.3389/fpls.2014.00093

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Abstract

Carpels are leaf-like structures that bear ovules, and thus play a crucial role in the plant life cycle. In angiosperms, carpels are the last organs produced by the floral meristem and they differentiate a specialized meristematic tissue from which ovules develop. Members of the three-amino-acid-loop-extension (TALE) class of homeoproteins constitute major regulators of meristematic activity. This family contains KNOTTED-like (KNOX) and BEL1-like (BLH or BELL) homeodomain proteins, which function as heterodimers. KNOX proteins can have different BELL partners, leading to multiple combinations with distinct activities, and thus regulate many aspects of plant morphogenesis, including gynoecium development. TALE proteins act primarily through direct regulation of hormonal pathways and key transcriptional regulators. This review focuses on the contribution of TALE proteins to gynoecium development and connects TALE transcription factors to carpel gene regulatory networks.

Highlights

In Arabidopsis, the female reproductive organ, or gynoecium, consists of an apical stigma, a style, and a basal ovary (Figure 1 and for reviews, Ferrándiz et al, 1999; Roeder and Yanofsky, 2006; Girin et al, 2009; Ferrándiz et al, 2010)
Members of the three-amino-acid-loop-extension (TALE) class of homeoproteins constitute major regulators of meristematic activity. This family contains KNOTTED-like (KNOX) and BEL1-like (BLH or BELL) homeodomain proteins, which function as heterodimers
This review focuses on the contribution of TALE proteins to gynoecium development and connectsTALE transcription factors to carpel gene regulatory networks

Summary

Nicolas Arnaud and Véronique Pautot*

UMR 1318 INRA-AgroParisTech, INRA Centre de Versailles-Grignon, Institut Jean-Pierre Bourgin, Versailles, France. North Carolina State University, USA Cristel C. Université Joseph Fourier of Grenoble, France Juan José Ripoll, University of California at San Diego, USA. Carpels are the last organs produced by the floral meristem and they differentiate a specialized meristematic tissue from which ovules develop. Members of the three-amino-acid-loop-extension (TALE) class of homeoproteins constitute major regulators of meristematic activity. This family contains KNOTTED-like (KNOX) and BEL1-like (BLH or BELL) homeodomain proteins, which function as heterodimers. KNOX proteins can have different BELL partners, leading to multiple combinations with distinct activities, and regulate many aspects of plant morphogenesis, including gynoecium development. This review focuses on the contribution of TALE proteins to gynoecium development and connectsTALE transcription factors to carpel gene regulatory networks

INTRODUCTION

Role of TALEs in gynoecium development