# Genome-Wide Identification and Characterization of the C2H2 Zinc Finger Gene Family in Pear (Pyrus bretschneideri) and Its Potential Role in Drought Stress Response

## TL;DR

This study identifies 52 C2H2 zinc finger genes in pear and explores their role in helping the plant respond to drought stress.

## Contribution

The first genome-wide characterization of the C2H2 zinc finger gene family in pear and its potential role in drought response.

## Key findings

- 52 PyC2H2 genes were identified and unevenly distributed across 17 pear chromosomes.
- Phylogenetic analysis grouped PyC2H2 genes into 10 clades with conserved motifs.
- Promoter analysis revealed drought-related regulatory elements, and gene expression varied under drought stress.

## Abstract

Drought stress severely limits pear growth and fruit production. This study identified 52 C2H2 zinc finger genes (PyC2H2) in pear and analyzed their features, evolution, and responses to drought. Key findings include uneven chromosomal distribution of these genes, evolutionary conservation with Arabidopsis thaliana, and drought-related regulatory elements in their promoters. Many PyC2H2 genes showed significant expression changes under drought—some were rapidly induced, others repressed. These genes likely regulate pear’s drought adaptation. The research provides foundational knowledge and candidate genes for breeding drought-tolerant pear varieties, helping reduce yield losses from drought and supporting sustainable fruit production.

C2H2-type zinc finger transcription factors play crucial roles in regulating plant growth and responses to abiotic stresses. Although pear is an economically important fruit crop with available genomic resources, the comprehensive analyses of its C2H2 gene family remain limited. In this study, we performed a genome-wide identification of C2H2 genes in pear, identifying 52 members that were unevenly distributed across 17 chromosomes. The predicted PyC2H2 proteins ranged from 343 to 1764 amino acids in length, with molecular weights between 12.4 and 62.7 kDa. Phylogenetic analysis classified these 52 PyC2H2 proteins into 10 classical clades, where genes with closer evolutionary relationships shared more similar conserved motifs. Collinearity analysis identified 37 collinear gene pairs between Arabidopsis thaliana and pear, suggesting evolutionary conservation. Promoter analysis revealed the presence of various cis-acting elements associated with hormone and stress responses, including Box 4, G-box, and GT1-motif. Additionally, the expression patterns of PyC2H2 genes differed among pear organs. These results provide valuable insights into the potential roles of PyC2H2 genes in drought stress responses and offer a foundation for future molecular breeding of drought-tolerant pear cultivars.