Nitric Oxide is required for Primary Nitrate Response in Arabidopsis. Evidence for S-nitrosation of NLP7

NEJAMKIN, ANDRES; DEL CASTELLO, FIORELLA; LAMATTINA, LORENZO; CORREA-ARAGUNDE, NATALIA; FORESI NOELIA

ANTIOXIDANTS & REDOX SIGNALING

MARY ANN LIEBERT INC

Año: 2023

1523-0864

AbstractAims: Nitrogen (N) is an essential nutrient for plant growth and seed production, being nitrate the main source of N in soils. Although several molecular players of plant responses to nitrate signaling were unraveled, it still remains a complex pathway with gaps demanding further investigation. The aim of our study is to analyze the role of Nitric Oxide (NO) in the Primary Nitrate Response (PNR).Results: Using a combination of genetic and pharmacological approaches, we demonstrate that NO is required for the expression of the nitrate-regulated genes NIA1, NIR, NRT1.1, and NRT2.1 in Arabidopsis. The PNR is blocked in the Arabidopsis mutant noa1, defective in NO production. Our results also show that Phytoglobin 1, involved in NO homeostasis, is rapidly induced during PNR in wt but not in mutants nrt1.1 and nlp7, suggesting that NRT1.1-NLP7 cascade modulates Phytoglobin expression. Biotin switch experiments demonstrate that NLP7, the PNR-master regulator, is S-nitrosated. NO appears to be not involved in the decrease of ROS concentration necessary for the PNR to take place, indicating that ROS and NO acts in independent ways. Besides, in the absence of NO, PNR does not occur even when the ROS concentration is low, indicating that the decrease in ROS concentration is a necessary but not sufficient condition for PNR to occur. Conclusion and Innovation: NO, a byproduct of nitrate metabolism and a well characterized signal molecule in plants, is a critical player in the PNR.