Figure 7.

Scheme summarizing the effects of low K on primary metabolism in root and shoot cells of Arabidopsis. Biochemical and transport pathways are indicated with solid and dashed arrows, respectively. Increases in metabolite concentrations and enzyme activities under K deficiency are shown in blue, and decreases are shown in red. Putative direct inhibition of PK by low K is indicated with the red bar. Dashed lines indicate the exchange of metabolites between roots and shoots. Negative electric charge is given as a circled minus. AA, Amino acids; N/C, N-C ratio of the total amino acid pool; NRT2, nitrate transporter 2.