Bailly, Aurélien Groenhagen, Ulrike Schulz, Stefan Geisler, Markus Eberl, Leo Weisskopf, Laure 2014-12-01 Recently, emission of volatile organic compounds (VOCs) has emerged as a mode of communication between bacteria and plants. Although some bacterial VOCs that promote plant growth have been identified, their underlying mechanism of action is unknown. Here we demonstrate that indole, which was identified using a screen for Arabidopsis growth promotion by VOCs from soil-borne bacteria, is a potent plant-growth modulator. Its prominent role in increasing the plant secondary root network is mediated by interfering with the auxin-signalling machinery. Using auxin reporter lines and classic auxin physiological and transport assays we show that the indole signal invades the plant body, reaches zones of auxin activity and acts in a polar auxin transport-dependent bimodal mechanism to trigger differential cellular auxin responses. Our results suggest that indole, beyond its importance as a bacterial signal molecule, can serve as a remote messenger to manipulate plant growth and development. application/pdf https://folia.unifr.ch/global/documents/303887 https://folia.unifr.ch/documents/303887/files/gei_ikv.pdf https://folia.unifr.ch/documents/303887/files/gei_ikv_sm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1111/tpj.12666 info:eu-repo/semantics/openAccess License undefined The Plant Journal. - 2014, vol. 80, no. 5, p. 758–771 plant microbe interaction volatile organic compounds auxin signalling root development Arabidopsis thaliana Escherichia coli plant growth promoting rhizobacteria info:eu-repo/classification/udc/57 The inter-kingdom volatile signal indole promotes root development by interfering with auxin signalling http://purl.org/coar/resource_type/c_6501