Figure 6.

Glc-responsive NRT2.1 protein accumulation and gene expression. Ler and gin2-1 seedlings were grown on either MS-N medium containing 0.3 mm NO₃⁻ as the sole N source (low nitrate; A and B) or MS medium (high nitrate; C and D) with 0.5% (w/v) Glc for 7 d. Seedlings were starved of Glc for 24 h before transfer to medium with 3% (w/v) Glc. Roots were harvested at the time of transfer (0h; black bars), 4 h (4h; white bars), or 24 h (24h; gray bars) after transfer. A and C show immunoblot detection of NRT2.1 and the loading control PIP1.1 in microsome extracts of 40 roots separated by 12% SDS-PAGE. B and D show NRT2.1 expression in the same root samples normalized against TUBULIN6. Values are means of three biological repeats ± se.