Biomaterial Database

Modulation of plant root growth by nitrogen source-defined regulation of polar auxin transport. 2021

Krisztina Ötvös, and Marco Marconi, and Andrea Vega, and Jose O'Brien, and Alexander Johnson, and Rashed Abualia, and Livio Antonielli, and Juan Carlos Montesinos, and Yuzhou Zhang, and Shutang Tan, and Candela Cuesta, and Christina Artner, and Eleonore Bouguyon, and Alain Gojon, and Jirí Friml, and Rodrigo A Gutiérrez, and Krzysztof Wabnik, and Eva Benková

Institute of Science and Technology (IST) Austria, Klosterneuburg, Austria.

Availability of the essential macronutrient nitrogen in soil plays a critical role in plant growth, development, and impacts agricultural productivity. Plants have evolved different strategies for sensing and responding to heterogeneous nitrogen distribution. Modulation of root system architecture, including primary root growth and branching, is among the most essential plant adaptions to ensure adequate nitrogen acquisition. However, the immediate molecular pathways coordinating the adjustment of root growth in response to distinct nitrogen sources, such as nitrate or ammonium, are poorly understood. Here, we show that growth as manifested by cell division and elongation is synchronized by coordinated auxin flux between two adjacent outer tissue layers of the root. This coordination is achieved by nitrate-dependent dephosphorylation of the PIN2 auxin efflux carrier at a previously uncharacterized phosphorylation site, leading to subsequent PIN2 lateralization and thereby regulating auxin flow between adjacent tissues. A dynamic computer model based on our experimental data successfully recapitulates experimental observations. Our study provides mechanistic insights broadening our understanding of root growth mechanisms in dynamic environments.