Reciprocal regulation between AtNRT2.1 and AtAMT1.1 expression and the kinetics of NH4+ and NO3− influxes

Abstract Our results show that AtNRT2.1 expression has a positive effect on the NH 4 + ion influx, mediated by the HATS, as also occurs with AtAMT1.1 expression on the NO 3 − ion influx. AtNRT2.1 expression plays a key role in the regulation of AtAMT1.1 expression and in the NH 4 + ion influx, differentiating the nitrogen source, and particularly, the lack of it. Nitrogen starvation produces a compensatory effect by AtAMT1.1 when there is an absence of the AtNRT2.1 gene. Our results also show that, in the atnrt2 mutant lacking both AtNRT2.1 and AtNRT2.2 , gene functions present different kinetic parameters on the NH 4 + ion influx mediated by the HATS, according to the source and availability of nitrogen. Finally, the absence of AMT1.1 also produces changes in the kinetic parameters of the NO 3 − influx, showing different V max values depending on the source of nitrogen available.