Figure 6.

Biomass accumulation in Arabidopsis mutant plants and lines complemented with ScAMT2;1 driven by the sugarcane endogenous promoter. (A) Fresh weight of homozygous lines of qko+p2ScAMT2;1::ScAMT2;1 subjected to 2 mM KNO₃ (${\text{NO}}_3^{-}$) or 0.2, 2, and 4 mM NH₄Cl (NH₄ ⁺) for 14 d. Bars indicate means ± SE (n = 30). Different letters indicate significant differences among means according to Tukey’s test (p ≤ 0.05). (B) Influx of ¹⁵N-labeled ammonium (NH₄ ⁺) into roots of qko and qko+p2ScAMT2;1::ScAMT2;1 lines upon 3-d exposure to N-free (-N), 2 mM ${\text{NO}}_3^{-}$, or 2 mM NH₄ ⁺ nutrient solution. Bars indicate means ± SE (n = 4). Asterisks indicate significant differences between qko and transgenic plants according to Student’s t test (*p < 0.10 and **p < 0.05).