The role of WOX genes in flower development

International audienceBackground WOX (Wuschel-like homeobOX) genes form a family of plant-specific HOMEODOMAIN transcription factors, the members of which play important developmental roles in a diverse range of processes. WOX genes were first identified as determining cell fate during embryo development, as well as playing important roles in maintaining stem cell niches in the plant. In recent years, new roles have been identified in plant architecture and organ development, particularly at the flower level. Scope In this review, the role of WOX genes in flower development and flower architecture is highlighted, as evidenced from data obtained in the last few years. The roles played by WOX genes in different species and different flower organs are compared, and differential functional recruitment of WOX genes during flower evolution is considered. Conclusions This review compares available data concerning the role of WOX genes in flower and organ architecture among different species of angiosperms, including representatives of monocots and eudicots (rosids and asterids). These comparative data highlight the usefulness of the WOX gene family for evo–devo studies of floral development

Time to stop: flower meristem termination.

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Time to stop : flower meristem termination

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Altering FVE/MSI4 results in a substantial increase of biomass in Arabidopsis-the functional analysis of an ontogenesis accelerator

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Time to Stop: Flower Meristem Termination1

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Altering FVE/MSI4 results in a substantial increase of biomass in Arabidopsis-the functional analysis of an ontogenesis accelerator

International audienc

Sepal shape variability is robust to cell size heterogeneity in Arabidopsis

Assess the impacts of uniform cell types on organ shape robustness using Arabidopsis sepal as the mode

REBELOTE, a regulator of floral determinacy in Arabidopsis thaliana, interacts with both nucleolar and nucleoplasmic proteins

The nucleoplasm and nucleolus are the two main territories of the nucleus. While specific functions are associated with each of these territories (such as mRNA synthesis in the nucleoplasm and ribosomal rRNA synthesis in thenucleolus), some proteins are known to be located in both. Here, we investigated the molecular function of REBELOTE (RBL), an Arabidopsis thalianaprotein previously characterized as a regulator of floral meristem termination. We show that RBL displays a dual localization, in the nucleolus and nucleoplasm. Moreover, we used direct and global approaches to demonstrate that RBL interacts with nucleic acid-binding proteins. It binds to the NOC proteins SWA2, AtNOC2 and AtNOC3 in both the nucleolus and nucleoplasm, and also to OBE1 and VFP3/ENAP1. Taking into account the identities of these RBL interactors, we hypothesise that RBL acts both in ribosomal biogenesis and in the regulation of gene expression

Sepal shape variability is robust to cell size heterogeneity in Arabidopsis

International audienceHow organisms produce organs with robust shapes and sizes is still an open question. In recent years, the Arabidopsis sepal has been used as a model system to study this question because of its highly reproducible shape and size. One interesting aspect of the sepal is that its epidermis contains cells of very different sizes. Previous reports have qualitatively shown that sepals with more or less giant cells exhibit comparable final size and shape. Here, we investigate this question using quantitative approaches. We find that a mixed population of cell size modestly contribute to the normal width of the sepal but is not essential for its shape robustness. Furthermore, in a mutant with increased cell and organ growth variability, the change in final sepal shape caused by giant cells is exaggerated but the shape robustness is not affected. This formally demonstrates that sepal shape variability is robust to cell size heterogeneity