# Genome‐Wide Identification and Expression Analysis of Pathogenesis‐Related Protein 1 in Sweet Potato and Its Two Relatives

## TL;DR

This study identifies and analyzes PR1 genes in sweet potato and related species, revealing their roles in immunity, development, and stress response.

## Contribution

The study provides the first genome-wide analysis of PR1 genes in sweet potato and two Ipomoea relatives, offering insights for molecular breeding.

## Key findings

- 33, 50, and 36 PR1 or PR1-like genes were identified in sweet potato, I. trifida, and I. triloba, respectively.
- Phylogenetic analysis grouped the genes into five clusters, indicating evolutionary divergence.
- Most sweet potato PR1 genes were downregulated under stress, except IbPR1-5, which was upregulated.

## Abstract

Pathogenesis‐related Protein 1 (PR1) is a core component of plant innate immunity and plays crucial roles in plant growth, development, and stress response, especially biological stress. However, limited information is available on the PR1 genes in sweet potato and other Ipomoea species. In this study, 33, 50, and 36 PR1 or PR1‐like genes were identified from sweet potato (
I. batatas
),
I. trifida,
and
I. triloba
, respectively. Phylogenetic analysis categorized these genes into five groups, reflecting their evolutionary divergence. Cis‐regulatory elements associated with light, hormone, and stress responses. Tissue‐specific expression profiling of
I. trifida
and
I. triloba
revealed high expression levels in the flowers and flower‐buds, indicating potential roles in reproductive developmental processes. Stress response analysis showed that most PR1 genes in sweet potato were downregulated under biotic and abiotic treatments, whereas IbPR1‐5 was consistently upregulated across all three stress conditions. Our study provides novel insights into the evolutionary dynamics of PR1 genes across the three Ipomoea genomes and contributes to the future molecular breeding of sweet potato cultivars.

Pathogenesis‐related Protein 1 (PR1) is a core component of plant innate immunity. We identified 33, 50, and 36 PR1 genes in
Ipomoea batatas
,
Ipomoea trifida
, and
Ipomoea triloba
. Phylogenetic analysis clustered them into 5 groups. Two diploid wild species show high flower/flower‐buds expression, and most sweet potato PR1s are downregulated under stress conditions, except IbPR1‐5. These findings provide valuable insights for the molecular breeding of sweet potato.