# The Influence of Zinc Oxide Nanoparticles and Salt Stress on the Morphological and Some Biochemical Characteristics of Solanum lycopersicum L. Plants

## TL;DR

This study shows that applying zinc oxide nanoparticles can help tomato plants resist salt stress by improving their growth and reducing harmful effects.

## Contribution

The study introduces the use of ZnO-NPs as a novel method to mitigate salt stress in tomato plants.

## Key findings

- ZnO-NPs improved plant growth and chlorophyll content under salt stress.
- ZnO-NPs reduced stress markers like H2O2 and MDA in tomato plants.
- ZnO-NPs increased phenolic compounds and proteins in tomato leaves.

## Abstract

Salinity reduces crop yields and quality, causing global economic losses. Zinc oxide nanoparticles (ZnO-NPs) improve plant physiological and metabolic processes and abiotic stress resistance. This study examined the effects of foliar ZnO-NPs at 75 and 150 mg/L on tomato Kecskeméti 549 plants to alleviate salt stress caused by 150 mM NaCl. The precipitation procedure produced ZnO-NPs that were characterized using UV-VIS, TEM, STEM, DLS, EDAX, Zeta potential, and FTIR. The study assessed TPCs, TFCs, total hydrolyzable sugars, total free amino acids, protein, proline, H2O2, and MDA along with plant height, stem width, leaf area, and SPAD values. The polyphenolic burden was also measured by HPLC. With salt stress, plant growth and chlorophyll content decreased significantly. The growth and development of tomato plants changed by applying the ZnO-NPs. Dosages of ZnO-NPs had a significant effect across treatments. ZnO-NPs also increased chlorophyll, reduced stress markers, and released phenolic chemicals and proteins in the leaves of tomatoes. ZnO-NPs reduce salt stress by promoting the uptake of minerals. ZnO-NPs had beneficial effects on tomato plants when subjected to salt stress, making them an alternate technique to boost resilience in saline soils or low-quality irrigation water. This study examined how foliar application of chemically synthesized ZnO-NPs to the leaves affected biochemistry, morphology, and phenolic compound synthesis with and without NaCl.