# Genome-Wide Identification, Characterization, and Comparison of C3HC4 Family Genes in Salt Tolerance Between Barley and Rice

## TL;DR

This study compares C3HC4 genes in barley and rice to understand how they differ in salt tolerance and how these genes could help improve crops under salty conditions.

## Contribution

The study identifies and compares C3HC4 genes in barley and rice, revealing their roles in salt tolerance and evolutionary conservation.

## Key findings

- Barley has 123 HvC3HC4 genes while rice has 90 OsC3HC4 genes, grouped into four conserved subgroups.
- C3HC4 genes in barley show energy-conserving strategies linked to higher salt tolerance.
- C3HC4 genes are evolutionarily conserved in salt-tolerant species, suggesting their importance in stress adaptation.

## Abstract

Soil salinization constitutes a major constraint on global agricultural production, with marked divergence in salt adaptation strategies between salt-tolerant barley (Hordeum vulgare) and salt-sensitive rice (Oryza sativa). This study systematically investigated the evolution and functional specialization of the C3HC4-type RING zinc finger gene family, known to mediate abiotic stress responses through E3 ubiquitin ligase activity, in these contrasting cereal species. Through comparative genomics, we identified 123 HvC3HC4 genes and 90 OsC3HC4 genes, phylogenetically classified into four conserved subgroups. Differences in C3HC4 genes in phylogenetic relationships, chromosomal distribution, gene structure, motif composition, gene duplication events, and cis-elements in the promoter region were observed between barley and rice. Moreover, HvC3HC4s in barley tissues preferentially adopted an energy-conserving strategy, which may be a key mechanism for barley’s higher salt tolerance. Additionally, we found that C3HC4 genes were evolutionarily conserved in salt-tolerant species. The current results reveal striking differences in salt tolerance between barley and rice mediated by the C3HC4 gene family and offer valuable insight for potential genetic engineering applications in improving crop resilience to salinity stress.