# Genome-wide analysis of Alfalfa AP2/ERF gene family and abiotic stress response

## TL;DR

This study identifies and analyzes AP2/ERF genes in alfalfa, revealing their roles in stress resistance and potential for improving crop resilience.

## Contribution

The first genome-wide analysis of AP2/ERF genes in alfalfa, identifying key stress-responsive genes for breeding purposes.

## Key findings

- 110 MsAP2/ERF genes were identified and mapped onto 28 chromosomes in alfalfa.
- 12 MsAP2/ERF genes were found to be differentially expressed under cold, salt, and drought stresses.
- Genes MsERF45, MsERF54, and MsERF55 showed significant responses to multiple abiotic stresses.

## Abstract

AP2/ERF transcription factors represent one of the largest gene families in plants, playing key roles in regulating growth, development, and responses to abiotic stresses. Alfalfa (Medicago sativa L.) is an important leguminous forage crop, whose growth and yield are often severely constrained by abiotic stresses.

In this study, we identified 110 MsAP2/ERF genes from the genome of the alfalfa cultivar ‘Xinjiang Daye’ through a genome-wide screening and mapped them onto 28 chromosomes. Gene duplication analysis revealed that this family has undergone extensive tandem duplication events and strong purifying selection during its evolution.

Collinearity analysis identified 104 and 33 putative orthologs between Medicago sativa and Medicago truncatula L. and Arabidopsis thaliana, respectively. These genes exhibit considerable diversity in gene structure and conserved protein motifs, and their promoter regions are enriched with various cis-acting elements related to abiotic stress responses. Based on publicly available transcriptome data, a total of 12 MsAP2/ERF genes were found to be differentially expressed under cold, salt, and drought stresses. Among them, several genes, including MsERF45, MsERF54, and MsERF55, showed significant responses to all three types of stress, as confirmed by RT-qPCR assays.

These findings provides valuable insights into the functions of MsAP2/ERF genes in stress resistance mechanisms in alfalfa to support future stress-tolerant alfalfa breeding efforts.