Figure 4.

Functional Expression of C-Terminally Modified AMT1;3 Variants in the Quadruple Insertion Line qko.

(A) Influx of ¹⁵N-labeled ammonium into roots of qko and two independent lines of qko-35S:AMT1;3, qko-35S:AMT1;3TA, or qko-35S:AMT1;3TD. Six-week-old Arabidopsis plants were precultured in nutrient solution containing 2 mM ammonium nitrate and subjected to N deficiency for a period of 4 d prior to influx analysis.¹⁵N-labeled ammonium was supplied at a concentration of 200 μM. Bars indicate means ± sd; n = 8 to 10. Significant differences at P < 0.01 according to Tukey’s test are indicated by different letters. DW, dry weight.

(B) Protein gel blot analysis of microsomal membrane fractions from roots of qko and one independent line of qko-35S:AMT1;3, qko-35S:AMT1;3TA, or qko-35S:AMT1;3TD using the anti-AMT1;3 antibody. Protein samples were pretreated either at 37°C in the presence of β-mercaptoethanol (reducing conditions; +βME) or at 0°C in the absence of β-mercaptoethanol (nonreducing conditions; −βME). MM, Magic Marker.

[See online article for color version of this figure.]