Local and long-range signaling pathways regulating plant responses to nitrate.
Nitrate is the major source of nitrogen (N) for plants growing in aerobic soils. However, the NO3- ion is also used by plants as a signal to reprogram plant metabolism and to trigger changes in plant architecture. A striking example is the way that a root system can react to a localized source of NO3- by activating the NO3- uptake system and proliferating lateral roots preferentially within the NO3(-)-rich zone. That roots are able to respond autonomously in this fashion implies the existence of local signaling pathways that are sensitive to local changes in the external NO3- concentration. On the other hand, long-range signaling pathways are also needed to modulate these responses according to the plant's N status and to coordinate the allocation of resources between the root and the shoot. This review examines these signaling mechanisms and their interactions with sugar-sensing and hormonal response pathways.
Forde
Brian G
BG
Department of Biological Sciences, Lancaster University, Lancaster, LA1 4YQ, United Kingdom. b.g.forde@lancaster.ac.uk
D009566:Nitrates / Q000502:physiology*; D063245:Plant Development; D018521:Plant Physiological Phenomena; D015398:Signal Transduction
D009566:Nitrates