Nitrate-Regulated Auxin Transport by NRT1.1 Defines a Mechanism for Nutrient Sensing in Plants

0343963 - ÚEB 2011 RIV US eng J - Journal Article
Krouk, G. - Lacombe, B. - Bielach, A. - Perrine-Walker, F. - Malínská, Kateřina - Mounier, E. - Hoyerová, Klára - Tillard, P. - Leon, S. - Ljung, K. - Zažímalová, Eva - Benková, E. - Nacry, P. - Gojon, A.
Nitrate-Regulated Auxin Transport by NRT1.1 Defines a Mechanism for Nutrient Sensing in Plants.
Developmental Cell. Roč. 18, č. 6 (2010), s. 927-937. ISSN 1534-5807. E-ISSN 1878-1551
R&D Projects: GA MŠMT(CZ) LC06034
Institutional research plan: CEZ:AV0Z50380511
Keywords : SIGNALING * DEVBIO * PROTEINS
Subject RIV: ED - Physiology
Impact factor: 13.946, year: 2010

Nitrate is both a nitrogen source for higher plants and a signal molecule regulating their development. In Arabidopsis, the NRT1.1 nitrate transporter is crucial for nitrate signaling governing root growth, and has been proposed to act as a nitrate sensor. However, the sensing mechanism is unknown. Herein we show that NRT1.1 not only transports nitrate but also facilitates uptake of the phytohormone auxin. Moreover, nitrate inhibits NRT1.1-dependent auxin uptake, suggesting that transduction of nitrate signal by NRT1.1 is associated with a modification of auxin transport. Among other effects, auxin stimulates lateral root development. Mutation of NRT1.1 enhances both auxin accumulation in lateral roots and growth of these roots at low, but not high, nitrate concentration. Thus, we propose that NRT1.1 represses root growth at low nitrate availability by promoting basipetal auxin transport out of these roots. This defines a mechanism connecting nutrient and hormone signaling during organ development.
Permanent Link: http://hdl.handle.net/11104/0186315