Figure 2.

Sugar and amino acid profiles among the fifteen Nicotiana species. (A) Sum of total sugar content highlighting the contributions of each of the three main sugars, sucrose, glucose and fructose. (B) Molar ratio of fructose to glucose. (C) Molar ratio of sucrose to the total hexose content. (D) Sum of total amino acid content highlighting the contributions of nonproteinaceous, essential, and nonessential amino acid categories. (E) Proportion of nonproteinaceous, essential, and nonessential amino acid categories. (F) Percentage and concentration (mM) of proline in each nectar. Error bars represent the standard error, from 6 replicates.