JAGGED Controls Arabidopsis Petal Growth and Shape by Interacting with a Divergent Polarity Field

• Published in: PLoS biology Vol. 11; no. 4; p. e1001550
• Main Authors: Sauret-Güeto, Susanna, Schiessl, Katharina, Bangham, Andrew, Sablowski, Robert, Coen, Enrico
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.04.2013; Public Library of Science (PLoS)
• Subjects: Arabidopsis - cytology; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis Proteins - physiology; Arabidopsis thaliana; Biology; Cell Cycle Proteins - physiology; Cell division; Developmental biology; Flowers - cytology; Flowers - growth & development; Flowers - metabolism; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Genotype & phenotype; Green Fluorescent Proteins - biosynthesis; Growth; Growth rate; Indoleacetic Acids - metabolism; Leaves; Membrane Transport Proteins - metabolism; Microscopy, Fluorescence; Models, Biological; Morphogenesis; Physiological aspects; Plant Growth Regulators - metabolism; Plant Leaves - cytology; Plant Leaves - growth & development; Plant Leaves - metabolism; Plants, Flowering of; Transcription Factors - genetics; Transcription Factors - metabolism; United Kingdom; Green Fluorescent Proteins; Arabidopsis; Plant Leaves; Flowers; Plant Growth Regulators; Morphogenesis; Arabidopsis Proteins; Gene Expression Regulation, Developmental; Models, Biological; Membrane Transport Proteins; Gene Expression Regulation, Plant; Transcription Factors; Cell Cycle Proteins; Microscopy, Fluorescence; Indoleacetic Acids
• ISSN: 1545-7885; 1544-9173; 1545-7885
• DOI: 10.1371/journal.pbio.1001550

A flowering plant generates many different organs such as leaves, petals, and stamens, each with a particular function and shape. These types of organ are thought to represent variations on a common underlying developmental program. However, it is unclear how this program is modulated under different selective constraints to generate the diversity of forms observed. Here we address this problem by analysing the development of Arabidopsis petals and comparing the results to models of leaf development. We show that petal development involves a divergent polarity field with growth rates perpendicular to local polarity increasing towards the distal end of the petal. The hypothesis is supported by the observed pattern of clones induced at various stages of development and by analysis of polarity markers, which show a divergent pattern. We also show that JAGGED (JAG) has a key role in promoting distal enhancement of growth rates and influences the extent of the divergent polarity field. Furthermore, we reveal links between the polarity field and auxin function: auxin-responsive markers such as DR5 have a broader distribution along the distal petal margin, consistent with the broad distal organiser of polarity, and PETAL LOSS (PTL), which has been implicated in the control of auxin dynamics during petal initiation, is directly repressed by JAG. By comparing these results with those from studies on leaf development, we show how simple modifications of an underlying developmental system may generate distinct forms, providing flexibility for the evolution of different organ functions.