# Integrated transcriptomic and metabolomic analysis reveals zinc oxide nanoparticles associated modulation of salt stress responses in Glycyrrhiza uralensis

## TL;DR

This study shows how zinc oxide nanoparticles help Glycyrrhiza uralensis plants handle salty soil better by boosting their defense systems.

## Contribution

The novel use of ZnO NPs to enhance salt stress resilience in G. uralensis through integrated transcriptomic and metabolomic analysis.

## Key findings

- ZnO NPs increased salt accumulation while maintaining plant photosynthesis and root growth.
- Salt stress disrupted phenylpropanoid and flavonoid pathways, altered root metabolism.
- ZnO NPs modulated gene expression and root metabolites, enhancing plant defense systems.

## Abstract

The depletion of wild Glycyrrhiza resources has made artificial cultivation essential; however, soil salinization severely limits the yield and quality of G. uralensis. Zinc oxide nanoparticles (ZnO NPs) exhibit promising potential in phytoremediation, yet their regulatory mechanisms under salt stress remain unclear. In this study, Glycyrrhiza uralensis was used to investigate the effects of salt stress and the modulating effects of ZnO NPs. Our results showed that ZnO NPs application enhanced salt accumulation in Glycyrrhiza uralensis while maintaining photosynthetic performance and root growth. Integrated transcriptomic and metabolomic analyses revealed that salt stress disrupted phenylpropanoid and flavonoid biosynthesis pathways, leading to detectable alterations in root metabolic profiles. Moreover, ZnO NPs modulated root metabolite accumulation and related gene expression, which further affected root metabolites and activated plant defense systems, contributing to enhanced root system adaptation and overall plant resilience under salt stress. These findings suggest that ZnO NPs treatment is associated with improved salt stress performance in G. uralensis under the present experimental conditions. This study provides insights into the potential application of ZnO nanoparticles in improving salt tolerance, thereby offering a promising strategy for the sustainable cultivation of Glycyrrhiza uralensis in saline-alkali soils.