# Genome-Wide Identification of RTE Gene Family Members in Sweet Potato and Their Expression Patterns Under Salt and Drought Stress

## TL;DR

This study identifies and analyzes RTE genes in sweet potato, revealing their potential role in helping the plant adapt to salt and drought stress.

## Contribution

The study reports the first genome-wide identification and expression analysis of RTE genes in sweet potato under abiotic stress.

## Key findings

- Twenty-three RTE genes were identified in sweet potato, distributed across 21 chromosomes and one scaffold.
- Most IbRTE genes showed tissue-specific and differential expression under drought and salt stress.
- qRT–PCR confirmed that 14 representative IbRTE genes have distinct expression patterns under salt and drought treatments.

## Abstract

Ethylene is a multifunctional phytohormone that regulates plant growth, development, and responses to abiotic/biotic stresses. RTE1 (Reversion-To-Ethylene Sensitivity1) acts as a negative regulator of the ethylene responses in Arabidopsis by positively regulating ethylene receptor ETR1. However, the role of RTE genes in sweet potato (Ipomoea batatas), an import food crop worldwide, remains largely unknown, particularly their involvement in abiotic stress adaptation. In this study, we identified 23 RTE genes in sweet potato, distributed across 21 chromosomes and one scaffold BrgTig00017944. The phylogenetic analysis divided them into two groups, the RTE1 group and RTH (RTE1-Homolog) group. Synteny analysis revealed that whole genome duplication (WGD) was the major force of expansion of the IbRTE gene family. Multiple cis-acting elements responsive to hormones and stress were found in the promoter region of IbRTE genes. The transcriptome expression profiling showed that the majority of IbRTEs have tissue-specific and differential expression under drought and salt stresses. Meanwhile, the qRT–PCR results showed that the 14 representatives IbRTEs have differential expression profilings under salt (NaCl) and drought (PEG) treatments. These findings suggest that the IbRTE genes may be involved in sweet potato’s adaptive responses to salt and drought, providing a valuable foundation for further functional studies.