--- res: bibo_abstract: - To control morphogenesis, molecular regulatory networks have to interfere with the mechanical properties of the individual cells of developing organs and tissues, but how this is achieved is not well known. We study this issue here in the shoot meristem of higher plants, a group of undifferentiated cells where complex changes in growth rates and directions lead to the continuous formation of new organs [1, 2]. Here, we show that the plant hormone auxin plays an important role in this process via a dual, local effect on the extracellular matrix, the cell wall, which determines cell shape. Our study reveals that auxin not only causes a limited reduction in wall stiffness but also directly interferes with wall anisotropy via the regulation of cortical microtubule dynamics. We further show that to induce growth isotropy and organ outgrowth, auxin somehow interferes with the cortical microtubule-ordering activity of a network of proteins, including AUXIN BINDING PROTEIN 1 and KATANIN 1. Numerical simulations further indicate that the induced isotropy is sufficient to amplify the effects of the relatively minor changes in wall stiffness to promote organogenesis and the establishment of new growth axes in a robust manner.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Massimiliano foaf_name: Sassi, Massimiliano foaf_surname: Sassi - foaf_Person: foaf_givenName: Olivier foaf_name: Ali, Olivier foaf_surname: Ali - foaf_Person: foaf_givenName: Frédéric foaf_name: Boudon, Frédéric foaf_surname: Boudon - foaf_Person: foaf_givenName: Gladys foaf_name: Cloarec, Gladys foaf_surname: Cloarec - foaf_Person: foaf_givenName: Ursula foaf_name: Abad, Ursula foaf_surname: Abad - foaf_Person: foaf_givenName: Coralie foaf_name: Cellier, Coralie foaf_surname: Cellier - foaf_Person: foaf_givenName: Xu foaf_name: Chen, Xu foaf_surname: Chen foaf_workInfoHomepage: http://www.librecat.org/personId=4E5ADCAA-F248-11E8-B48F-1D18A9856A87 - foaf_Person: foaf_givenName: Benjamin foaf_name: Gilles, Benjamin foaf_surname: Gilles - foaf_Person: foaf_givenName: Pascale foaf_name: Milani, Pascale foaf_surname: Milani - foaf_Person: foaf_givenName: Jirí foaf_name: Friml, Jirí foaf_surname: Friml foaf_workInfoHomepage: http://www.librecat.org/personId=4159519E-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0002-8302-7596 - foaf_Person: foaf_givenName: Teva foaf_name: Vernoux, Teva foaf_surname: Vernoux - foaf_Person: foaf_givenName: Christophe foaf_name: Godin, Christophe foaf_surname: Godin - foaf_Person: foaf_givenName: Olivier foaf_name: Hamant, Olivier foaf_surname: Hamant - foaf_Person: foaf_givenName: Jan foaf_name: Traas, Jan foaf_surname: Traas bibo_doi: 10.1016/j.cub.2014.08.036 bibo_issue: '19' bibo_volume: 24 dct_date: 2014^xs_gYear dct_language: eng dct_publisher: Cell Press@ dct_title: An auxin-mediated shift toward growth isotropy promotes organ formation at the shoot meristem in Arabidopsis@ ...