Plants are able to modulate root growth and development to optimize their nitrogen nutrition. In Arabidopsis (Arabidopsis thaliana), the adaptive root response to nitrate (NO3 -) depends on the NRT1.1/NPF6.3 transporter/sensor. NRT1.1 represses emergence of lateral root primordia (LRPs) at low concentration or absence of NO3 - through its auxin transport activity that lowers auxin accumulation in LR. However, these functional data strongly contrast with the known transcriptional regulation of NRT1.1, which is markedly repressed in LRPs in the absence of NO3 -. To explain this discrepancy, we investigated in detail the spatiotemporal expression pattern of the NRT1.1 protein during LRP development and combined local transcript analysis with the use of transgenic lines expressing tagged NRT1.1 proteins. Our results show that although NO3 - stimulates NRT1.1 transcription and probably mRNA stability both in primary root tissues and in LRPs, it acts differentially on protein accumulation, depending on the tissues considered with stimulation in cortex and epidermis of the primary root and a strong repression in LRPs and to a lower extent at the primary root tip. This demonstrates that NRT1.1 is strongly regulated at the posttranscriptional level by tissue-specific mechanisms. These mechanisms are crucial for controlling the large palette of adaptive responses to NO3 - mediated by NRT1.1 as they ensure that the protein is present in the proper tissue under the specific conditions where it plays a signaling role in this particular tissue.
This work was supported by the Agropolis Foundation (RHIZOPOLIS project to A.G. and P.N., and RTRA 2009-2011 project to F.P.-W.), the Knowledge Biobase Economy European project (KBBE-005-002 Root enhancement for crop improvement to M.P. and P.N.), and the European EURoot project (FP7-KBBE-2011-5 to J.R., A.G., and P.N.). We thank Carine Alcon for the help with analysis of confocal images, Xavier Dumont for assistance with Arabidopsis transformations, staff members of the Institut de Biologie Intégrative des Plantes for technical assistance with biological material culture, and students and trainees for assistance with laboratory work. Confocal observations were made at the Montpellier RIO Imaging facility.
1237 - 1248
Bouguyon E, Perrine Walker F, Pervent M, et al. Nitrate controls root development through posttranscriptional regulation of the NRT1.1/NPF6.3 transporter sensor. Plant Physiology. 2016;172(2):1237-1248. doi:10.1104/pp.16.01047
Bouguyon, E., Perrine Walker, F., Pervent, M., Rochette, J., Cuesta, C., Benková, E., … Nacry, P. (2016). Nitrate controls root development through posttranscriptional regulation of the NRT1.1/NPF6.3 transporter sensor. Plant Physiology, 172(2), 1237–1248. https://doi.org/10.1104/pp.16.01047
Bouguyon, Eléonore, Francine Perrine Walker, Marjorie Pervent, Juliette Rochette, Candela Cuesta, Eva Benková, Alexandre Martinière, et al. “Nitrate Controls Root Development through Posttranscriptional Regulation of the NRT1.1/NPF6.3 Transporter Sensor.” Plant Physiology 172, no. 2 (2016): 1237–48. https://doi.org/10.1104/pp.16.01047.
E. Bouguyon et al., “Nitrate controls root development through posttranscriptional regulation of the NRT1.1/NPF6.3 transporter sensor,” Plant Physiology, vol. 172, no. 2, pp. 1237–1248, 2016.
Bouguyon E, Perrine Walker F, Pervent M, Rochette J, Cuesta C, Benková E, Martinière A, Bach L, Krouk G, Gojon A, Nacry P. 2016. Nitrate controls root development through posttranscriptional regulation of the NRT1.1/NPF6.3 transporter sensor. Plant Physiology. 172(2), 1237–1248.
Bouguyon, Eléonore, et al. “Nitrate Controls Root Development through Posttranscriptional Regulation of the NRT1.1/NPF6.3 Transporter Sensor.” Plant Physiology, vol. 172, no. 2, American Society of Plant Biologists, 2016, pp. 1237–48, doi:10.1104/pp.16.01047.
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