Work

Genome-wide identification of the BCAT gene family in Zygophyllum brachypterum and functional characterization of ZbBCAT2 in salt stress response

Year: 2026

Type: article

Abstract: Soil salinization is a major abiotic stress limiting plant growth and stress adaptation. Branched-chain amino acid aminotransferases (BCATs) govern branched-chain amino acid (BCAA) metabolic homeostasis and are closely associated with plant abiotic stress tolerance, yet their genome-wide characteristics and functions in the desert halophyte Zygophyllum brachypterum remain unknown. In this study, five ZbBCAT genes were identified at the genome-wide level and systematically characterized via phylogenetic, syntenic, structural and promoter cis-element analyses; their spatiotemporal expression profiles under salt stress were determined by qRT-PCR, and the function of the core candidate ZbBCAT2 ( Zb8G000817 ) was verified via heterologous overexpression in Arabidopsis thaliana and Oryza sativa . The results showed that the five ZbBCAT members clustered into three evolutionary subfamilies with marked monocot–dicot divergence; ZbBCAT2 was the only member consistently and strongly induced by salt stress across roots, stems and leaves with the highest upregulation amplitude; and ZbBCAT2 overexpression exacerbated salt stress damage and reduced survival rates in both A. thaliana and O. sativa , while the bcat2 mutant exhibited enhanced tolerance, revealing that ZbBCAT2 exerts consistent negative regulatory effects on salt tolerance when heterologously expressed in both dicot and monocot plant systems. This study provides systematic insights into the ZbBCAT family and identifies ZbBCAT2 as a key negative regulator of salt tolerance, offering candidate genes and mechanistic references for plant salt tolerance improvement.

Source: Frontiers in Plant Science

DOI: 10.3389/fpls.2026.1978750