Nitrate reductase is a key enzyme responsible for nitrogen-regulated auxin accumulation in Arabidopsis roots. 

 -  BioChemical and Biophysical Research Communications, 532(4), p.633-639., 2020 .
<br/><br/> Nitrate reductase (NR)is one of the key enzymes for plant nitrogen assimilation and root architecture remodeling. However, crosstalk between NR-mediated signaling and auxin-mediated root development in nitrogen-status responses has not been investigated in details before. In this study, root phenotype and auxin distribution in nia1/nia2 (nitrate reductase)double mutant and chl1-5 (nitrate transporter NRT1.1)mutant under different nitrogen availabilities were compared. The nia1/nia2 mutant showed very low expression levels of auxin biosynthetic/signaling genes and was insensitive to nitrogen changes. While the chl1-5 mutant showed a high NR activity with a high level of auxin in the meristematic zone and a weaker response to nitrogen changes, when compared with the wild-type plants. We firstly found that NR activity was roughly positive-correlated with the root auxin level, and there is a crosstalk between nitrate signaling and auxin signaling. The putative signaling pathways downstream of NR have been discussed. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>NITRATE REDUCTASE<br/>NITRATE TRANSPORTER NRT1.1<br/>NITRATE SIGNALING<br/>ROOT ARCHITECTURE REMODELING<br/>AUXIN BIOSYNTHESIS AND TRANSPORT