Table 1.

NiR Activity and Estimated Ks for Nitrite Transport Activity from Intact Chloroplasts

StrainsKs for Nitrite Transport
Activitya (μM)
NiR Activity
(mU/mg Chl)b
JA4 (Nar1)NDc1163±381 (n = 3)
AU3 (Nar1+)4.8±3.8 (n = 3)  778±29 (n = 3)
WT (Nar1+)5.5±1.6 (n = 3)  579±37 (n = 3)
PAD41 (Nar1)ND  857±182 (n = 3)
AD7 (Nar1+)8±4 (n = 3)  715±122 (n = 3)
D2 (Nar1)d7  956
AD3 (Nar1+)d3  842
  • a Ks was determined from the progress curves (Galván et al., 1996). Statistical values represent the mean ±sd from three independent experiments.

  • b mU, nmol nitrite hr–1; Chl, chlorophyll.

  • c ND, not determinable under our experimental conditions.

  • d Data for strains D2 and AD3 correspond to a representative experiment from two independent ones.