Affiliation: | (1) Department of Biological Sciences, Lancaster University, Lancaster, Bailrigg, UK, LA1 4YQ;(2) Present address: Centre for Novel Agricultural Products, University of York, Heslington, York, UK |
Abstract: | During their life cycle, plants must be able to adapt to wide variations in the supply of soil nitrogen (N). Changes in N availability, and in the relative concentrations of NO3−and NH4+, are known to have profound regulatory effects on the N uptake systems in the root, on C and N metabolism throughout the plant, and on root and shoot morphology. Optimising the plant’s responses to fluctuations in the N supply requires co-ordination of the pathways of C and N assimilation, as well as establishment of the appropriate allocation of resources between root and shoot growth. Achieving this integration of responses at the whole plant level implies long-distance signaling mechanisms that can communicate information about the current availability of N from root-to-shoot, and information about the C/N status of the shoot in the reverse direction. In this review we will discuss recent advances which have contributed to our understanding of these long-range signaling pathways. |