Figure 1.

The central role of glutamine/glutamate in plant metabolism. The central role of glutamine/glutamate in plant metabolism is represented schematically. Plain arrows indicate the enzymatic reactions catalysed by glutamine synthetase (1) and glutamate synthase (2). Dashed arrows represent pathways that feed into or are affected by these two key amino acids. The representation is inspired by Forde and Lea [48].