# Expression of the Suaeda salsa SsNLP7 Transcription Factor in Solanum lycopersicum Enhances Its Salt Tolerance

## TL;DR

This study shows that expressing the SsNLP7 gene from a salt-tolerant plant in tomatoes improves their ability to withstand salt stress.

## Contribution

The study reveals the positive role of SsNLP7A in enhancing salt tolerance in tomatoes through multiple physiological and molecular mechanisms.

## Key findings

- SsNLP7A overexpression promotes root development and reduces salt-induced growth inhibition in tomatoes.
- Transgenic plants show higher chlorophyll, osmotic regulators, and antioxidant enzyme activity under salt stress.
- Transcriptome analysis links SsNLP7A to regulation of carbon metabolism, phytohormone signaling, and antioxidant pathways.

## Abstract

The nitrate signaling core regulator NLP7 is known to negatively regulate salt tolerance in Arabidopsis thaliana, but the function of the (SsNLP7A) gene in the halophyte Suaeda salsa remains unclear. To investigate whether SsNLP7A participates in salt stress responses, this study heterologously overexpressed the gene in tomato (Solanum lycopersicum) and systematically evaluated its function under salt stress through phenotypic, physiological, and transcriptomic analyses. The results indicate that SsNLP7A overexpression significantly promotes tomato root development and alleviates growth inhibition caused by salt stress. Under salt treatment, transgenic plants exhibited significantly higher chlorophyll content, accumulation of osmotic regulators (proline and soluble sugars), and antioxidant enzyme (POD, CAT, SOD) activity compared to wild-type plants. Transcriptome analysis further revealed that SsNLP7A enhances salt tolerance by regulating carbon metabolism, phytohormone signaling pathway, photosynthesis, and antioxidant pathways. Collectively, this study elucidates the positive regulatory role of SsNLP7A in salt stress response, providing new insights into its molecular mechanisms.