TY - JOUR

T1 - How do plants sense their nitrogen status?

AU - Gent, Lucas

AU - Forde, Brian G.

N1 - This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Journal of Experimental Botany following peer review. The definitive publisher-authenticated version Lucas Gent, Brian G. Forde; How do plants sense their nitrogen status?. J Exp Bot 2017; 68 (10): 2531-2539. doi: 10.1093/jxb/erx013 is available online at: https://academic.oup.com/jxb/article-lookup/doi/10.1093/jxb/erx013

PY - 2017/5/1

Y1 - 2017/5/1

N2 - The primary processes that contribute to the efficient capture of soil nitrate are the development of a root system that effectively explores the soil and the expression of high-affinity nitrate uptake systems in those roots. Both these processes are highly regulated to take into account the availability and distribution of external nitrate pools and the endogenous N status of the plant. While significant progress has been made in elucidating the early steps in sensing and responding to external nitrate, there is much less clarity about how the plant monitors its N status. This review specifically addresses the questions of what N compounds are sensed and in which part of the plant, as well as the identity of the signalling pathways responsible for their detection. Candidates that are considered for the role of N sensory systems include the target of rapamycin (TOR) signalling pathway, the general control non-derepressible 2 (GCN2) pathway, the plastidic PII-dependent pathway, and the family of glutamate-like receptors (GLRs). However, despite significant recent progress in elucidating the function and mode of action of these signalling systems, there is still much uncertainty about the extent to which they contribute to the process by which plants monitor their N status. The possibility is discussed that the large GLR family of Ca2+ channels, which are gated by a wide range of different amino acids and expressed throughout the plant, could act as amino acid sensors upstream of a Ca2+-regulated signalling pathway, such as the TOR pathway, to regulate the plant’s response to changes in N status.

AB - The primary processes that contribute to the efficient capture of soil nitrate are the development of a root system that effectively explores the soil and the expression of high-affinity nitrate uptake systems in those roots. Both these processes are highly regulated to take into account the availability and distribution of external nitrate pools and the endogenous N status of the plant. While significant progress has been made in elucidating the early steps in sensing and responding to external nitrate, there is much less clarity about how the plant monitors its N status. This review specifically addresses the questions of what N compounds are sensed and in which part of the plant, as well as the identity of the signalling pathways responsible for their detection. Candidates that are considered for the role of N sensory systems include the target of rapamycin (TOR) signalling pathway, the general control non-derepressible 2 (GCN2) pathway, the plastidic PII-dependent pathway, and the family of glutamate-like receptors (GLRs). However, despite significant recent progress in elucidating the function and mode of action of these signalling systems, there is still much uncertainty about the extent to which they contribute to the process by which plants monitor their N status. The possibility is discussed that the large GLR family of Ca2+ channels, which are gated by a wide range of different amino acids and expressed throughout the plant, could act as amino acid sensors upstream of a Ca2+-regulated signalling pathway, such as the TOR pathway, to regulate the plant’s response to changes in N status.

KW - Amino acids

KW - GCN2

KW - glutamate receptors

KW - nitrate uptake

KW - PII

KW - root development

KW - signal transduction

KW - target of rifampicin

U2 - 10.1093/jxb/erx013

DO - 10.1093/jxb/erx013

M3 - Journal article

C2 - 28201547

VL - 68

SP - 2531

EP - 2539

JO - Journal of Experimental Botany

JF - Journal of Experimental Botany

SN - 0022-0957

IS - 10

ER -