TY - JOUR AB - Mineral nutrition is one of the key environmental factors determining plant development and growth. Nitrate is the major form of macronutrient nitrogen that plants take up from the soil. Fluctuating availability or deficiency of this element severely limits plant growth and negatively affects crop production in the agricultural system. To cope with the heterogeneity of nitrate distribution in soil, plants evolved a complex regulatory mechanism that allows rapid adjustment of physiological and developmental processes to the status of this nutrient. The root, as a major exploitation organ that controls the uptake of nitrate to the plant body, acts as a regulatory hub that, according to nitrate availability, coordinates the growth and development of other plant organs. Here, we identified a regulatory framework, where cytokinin response factors (CRFs) play a central role as a molecular readout of the nitrate status in roots to guide shoot adaptive developmental response. We show that nitrate-driven activation of NLP7, a master regulator of nitrate response in plants, fine tunes biosynthesis of cytokinin in roots and its translocation to shoots where it enhances expression of CRFs. CRFs, through direct transcriptional regulation of PIN auxin transporters, promote the flow of auxin and thereby stimulate the development of shoot organs. AU - Abualia, Rashed AU - Ötvös, Krisztina AU - Novák, Ondřej AU - Bouguyon, Eleonore AU - Domanegg, Kevin AU - Krapp, Anne AU - Nacry, Philip AU - Gojon, Alain AU - Lacombe, Benoit AU - Benková, Eva ID - 11734 IS - 31 JF - Proceedings of the National Academy of Sciences of the United States of America TI - Molecular framework integrating nitrate sensing in root and auxin-guided shoot adaptive responses VL - 119 ER - TY - JOUR AB - 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. AU - Ötvös, Krisztina AU - Marconi, Marco AU - Vega, Andrea AU - O’Brien, Jose AU - Johnson, Alexander J AU - Abualia, Rashed AU - Antonielli, Livio AU - Montesinos López, Juan C AU - Zhang, Yuzhou AU - Tan, Shutang AU - Cuesta, Candela AU - Artner, Christina AU - Bouguyon, Eleonore AU - Gojon, Alain AU - Friml, Jiří AU - Gutiérrez, Rodrigo A. AU - Wabnik, Krzysztof T AU - Benková, Eva ID - 9010 IS - 3 JF - EMBO Journal SN - 02614189 TI - Modulation of plant root growth by nitrogen source-defined regulation of polar auxin transport VL - 40 ER - TY - JOUR AB - Nitrate commands genome-wide gene expression changes that impact metabolism, physiology, plant growth, and development. In an effort to identify new components involved in nitrate responses in plants, we analyze the Arabidopsis thaliana root phosphoproteome in response to nitrate treatments via liquid chromatography coupled to tandem mass spectrometry. 176 phosphoproteins show significant changes at 5 or 20 min after nitrate treatments. Proteins identified by 5 min include signaling components such as kinases or transcription factors. In contrast, by 20 min, proteins identified were associated with transporter activity or hormone metabolism functions, among others. The phosphorylation profile of NITRATE TRANSPORTER 1.1 (NRT1.1) mutant plants was significantly altered as compared to wild-type plants, confirming its key role in nitrate signaling pathways that involves phosphorylation changes. Integrative bioinformatics analysis highlights auxin transport as an important mechanism modulated by nitrate signaling at the post-translational level. We validated a new phosphorylation site in PIN2 and provide evidence that it functions in primary and lateral root growth responses to nitrate. AU - Vega, Andrea AU - Fredes, Isabel AU - O’Brien, José AU - Shen, Zhouxin AU - Ötvös, Krisztina AU - Abualia, Rashed AU - Benková, Eva AU - Briggs, Steven P. AU - Gutiérrez, Rodrigo A. ID - 9913 IS - 9 JF - EMBO Reports SN - 1469-221X TI - Nitrate triggered phosphoproteome changes and a PIN2 phosphosite modulating root system architecture VL - 22 ER - TY - THES AB - Nitrogen is an essential macronutrient determining plant growth, development and affecting agricultural productivity. Root, as a hub that perceives and integrates local and systemic signals on the plant’s external and endogenous nitrogen resources, communicates with other plant organs to consolidate their physiology and development in accordance with actual nitrogen balance. Over the last years, numerous studies demonstrated that these comprehensive developmental adaptations rely on the interaction between pathways controlling nitrogen homeostasis and hormonal networks acting globally in the plant body. However, molecular insights into how the information about the nitrogen status is translated through hormonal pathways into specific developmental output are lacking. In my work, I addressed so far poorly understood mechanisms underlying root-to-shoot communication that lead to a rapid re-adjustment of shoot growth and development after nitrate provision. Applying a combination of molecular, cell, and developmental biology approaches, genetics and grafting experiments as well as hormonal analytics, I identified and characterized an unknown molecular framework orchestrating shoot development with a root nitrate sensory system. AU - Abualia, Rashed ID - 10303 SN - 2663-337X TI - Role of hormones in nitrate regulated growth ER - TY - JOUR AB - Plant hormones as signalling molecules play an essential role in the control of plant growth and development. Typically, sites of hormonal action are usually distant from the site of biosynthesis thus relying on efficient transport mechanisms. Over the last decades, molecular identification of proteins and protein complexes involved in hormonal transport has started. Advanced screens for genes involved in hormonal transport in combination with transport assays using heterologous systems such as yeast, insect, or tobacco BY2 cells or Xenopus oocytes provided important insights into mechanisms underlying distribution of hormones in plant body and led to identification of principal transporters for each hormone. This review gives a short overview of the mechanisms of hormonal transport and transporters identified in Arabidopsis thaliana. AU - Abualia, Rashed AU - Benková, Eva AU - Lacombe, Benoît ID - 47 JF - Advances in Botanical Research TI - Transporters and mechanisms of hormone transport in arabidopsis VL - 87 ER -