The nitrate transporter NRT2.1 directly antagonizes PIN7-mediated auxin transport for root growth adaptation.
Proc Natl Acad Sci U S A
; 120(25): e2221313120, 2023 06 20.
Article
en En
| MEDLINE
| ID: mdl-37307446
ABSTRACT
As a crucial nitrogen source, nitrate (NO3-) is a key nutrient for plants. Accordingly, root systems adapt to maximize NO3- availability, a developmental regulation also involving the phytohormone auxin. Nonetheless, the molecular mechanisms underlying this regulation remain poorly understood. Here, we identify low-nitrate-resistant mutant (lonr) in Arabidopsis (Arabidopsis thaliana), whose root growth fails to adapt to low-NO3- conditions. lonr2 is defective in the high-affinity NO3- transporter NRT2.1. lonr2 (nrt2.1) mutants exhibit defects in polar auxin transport, and their low-NO3--induced root phenotype depends on the PIN7 auxin exporter activity. NRT2.1 directly associates with PIN7 and antagonizes PIN7-mediated auxin efflux depending on NO3- levels. These results reveal a mechanism by which NRT2.1 in response to NO3- limitation directly regulates auxin transport activity and, thus, root growth. This adaptive mechanism contributes to the root developmental plasticity to help plants cope with changes in NO3- availability.
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MEDLINE
Asunto principal:
Arabidopsis
/
Transportadores de Nitrato
Idioma:
En
Año:
2023
Tipo del documento:
Article