The interplay of carbon and nitrogen distribution: Prospects for improved crop yields

Growth and productivity of plants primarily depend on the balanced distribution of carbon (C) and nitrogen (N) among different organs. Previous studies on crop improvement have focussed on the C or N assimilation and distribution. However, recent findings reveal that C and N form a complex integrated network and are often dependent on each other to affect crop productivity. The underlying physiological and molecular mechanisms involved in the coordinated distribution of C and N among different plant organs are yet to be fully uncovered. Crucial roles in regulating C and N balance are played by transporters that mediate their movement across different organs. In Cotton, which has an indeterminate growth pattern, source–sink assimilate distribution could be a major bottleneck impeding fibre productivity. This review summarises our current understanding of C and N transport mechanisms, explores and compares different physiological and molecular approaches involved in the C–N distribution cascade, including cotton and other plant species. A comprehensive understanding of these integrated regulatory mechanisms is crucial for improving crop yields and fibre productivity.