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Plant Nitrogen Acquisition Under Low Availability: Regulation of Uptake and Root Architecture.

Kiba T, Krapp A - Plant Cell Physiol. (2016)

Bottom Line: One of the most important responses is the regulation of nitrogen acquisition efficiency.This review provides an update on the molecular determinants of two major drivers of the nitrogen acquisition efficiency: (i) uptake activity (e.g. high-affinity nitrogen transporters) and (ii) root architecture (e.g. low-nitrogen-availability-specific regulators of primary and lateral root growth).Major emphasis is laid on the regulation of these determinants by nitrogen supply at the transcriptional and post-transcriptional levels, which enables plants to optimize nitrogen acquisition efficiency under low nitrogen availability.

View Article: PubMed Central - PubMed

Affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro, Tsurumi, Yokohama, 230-0045 Japan takatoshi.kiba@riken.jp anne.krapp@versailles.inra.fr.

No MeSH data available.


A model of low N availability signaling pathways involved in the regulation of high-affinity N transporter gene expression and root architecture in Arabidopsis. Signaling pathways regulating (A) the expression of high-affinity N transporter genes (AtNRT2 and AtAMT genes) and (B) primary root (PR) growth, and/or lateral root (LR) growth and development under low N availability are depicted. Only pathways described in this review are shown. Red arrows and black blunted lines indicate positive and negative interactions, respectively. CK, cytokinin
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pcw052-F2: A model of low N availability signaling pathways involved in the regulation of high-affinity N transporter gene expression and root architecture in Arabidopsis. Signaling pathways regulating (A) the expression of high-affinity N transporter genes (AtNRT2 and AtAMT genes) and (B) primary root (PR) growth, and/or lateral root (LR) growth and development under low N availability are depicted. Only pathways described in this review are shown. Red arrows and black blunted lines indicate positive and negative interactions, respectively. CK, cytokinin

Mentions: Generally the expression of genes encoding high-affinity transporters of mineral nutrients is induced (or derepressed) under low substrate availability. This is also the case for all AtAMT1 and AtNRT2 genes involved in uptake, as described above. A reduction of the internal pool of glutamine and/or derived metabolites is thought to be one of the signals for induction (Lejay et al. 1999, Rawat et al. 1999, Yuan et al. 2007a, Nacry et al. 2013). Recently AtNPF6.3 was shown to be involved in the negative regulation of induction under high N availability. In the knockout mutant of AtNPF6.3 (chl1-5) grown under high N availability, the expression of high-affinity N transporter genes including AtNRT2.1, AtNRT2.4 and AtAMT1;3 was derepressed (Fig. 2A; Munos et al. 2004, Bouguyon et al. 2015). Phosphorylation of the threonine (T) 101 residue (T101) plays a role in this regulation. Introducing the phosphomimetic mutant form AtNPF6.3T101D into chl1-5 restored repression, but the non-phosphorylatable mutant form AtNPF6.3T101A did not. However, how low N availability is sensed and how the signal is transduced through phosphorylation of AtNPF6.3 is still unknown.Fig. 2


Plant Nitrogen Acquisition Under Low Availability: Regulation of Uptake and Root Architecture.

Kiba T, Krapp A - Plant Cell Physiol. (2016)

A model of low N availability signaling pathways involved in the regulation of high-affinity N transporter gene expression and root architecture in Arabidopsis. Signaling pathways regulating (A) the expression of high-affinity N transporter genes (AtNRT2 and AtAMT genes) and (B) primary root (PR) growth, and/or lateral root (LR) growth and development under low N availability are depicted. Only pathways described in this review are shown. Red arrows and black blunted lines indicate positive and negative interactions, respectively. CK, cytokinin
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4836452&req=5

pcw052-F2: A model of low N availability signaling pathways involved in the regulation of high-affinity N transporter gene expression and root architecture in Arabidopsis. Signaling pathways regulating (A) the expression of high-affinity N transporter genes (AtNRT2 and AtAMT genes) and (B) primary root (PR) growth, and/or lateral root (LR) growth and development under low N availability are depicted. Only pathways described in this review are shown. Red arrows and black blunted lines indicate positive and negative interactions, respectively. CK, cytokinin
Mentions: Generally the expression of genes encoding high-affinity transporters of mineral nutrients is induced (or derepressed) under low substrate availability. This is also the case for all AtAMT1 and AtNRT2 genes involved in uptake, as described above. A reduction of the internal pool of glutamine and/or derived metabolites is thought to be one of the signals for induction (Lejay et al. 1999, Rawat et al. 1999, Yuan et al. 2007a, Nacry et al. 2013). Recently AtNPF6.3 was shown to be involved in the negative regulation of induction under high N availability. In the knockout mutant of AtNPF6.3 (chl1-5) grown under high N availability, the expression of high-affinity N transporter genes including AtNRT2.1, AtNRT2.4 and AtAMT1;3 was derepressed (Fig. 2A; Munos et al. 2004, Bouguyon et al. 2015). Phosphorylation of the threonine (T) 101 residue (T101) plays a role in this regulation. Introducing the phosphomimetic mutant form AtNPF6.3T101D into chl1-5 restored repression, but the non-phosphorylatable mutant form AtNPF6.3T101A did not. However, how low N availability is sensed and how the signal is transduced through phosphorylation of AtNPF6.3 is still unknown.Fig. 2

Bottom Line: One of the most important responses is the regulation of nitrogen acquisition efficiency.This review provides an update on the molecular determinants of two major drivers of the nitrogen acquisition efficiency: (i) uptake activity (e.g. high-affinity nitrogen transporters) and (ii) root architecture (e.g. low-nitrogen-availability-specific regulators of primary and lateral root growth).Major emphasis is laid on the regulation of these determinants by nitrogen supply at the transcriptional and post-transcriptional levels, which enables plants to optimize nitrogen acquisition efficiency under low nitrogen availability.

View Article: PubMed Central - PubMed

Affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro, Tsurumi, Yokohama, 230-0045 Japan takatoshi.kiba@riken.jp anne.krapp@versailles.inra.fr.

No MeSH data available.