Genome analysis maps 540 GST genes across four legumes

A genome-wide study identified 540 glutathione S-transferase, or GST, superfamily members across four legume species: alfalfa, barrel medic, soybean and peanut. The analysis found that gene numbers were positively correlated with genome size and ploidy level, while phylogenetic classification divided the genes into nine subfamilies, with Tau predominating in every species examined.

The researchers assessed how the GST family expanded across the four plant genomes. Whole-genome duplication and segmental duplication emerged as the primary drivers of family expansion. Evolutionary analysis also indicated that the superfamily evolved predominantly under purifying selection across the sampled legumes. One exception was the soybean-specific tandem duplicate pair GmGSTU18 and GmGSTU19, which showed evidence of positive selection. The findings describe patterns within the analyzed gene family and do not establish changes in crop performance.

Promoter analysis identified 24 types of cis-acting elements associated with growth, metabolism and stress responses. Tau and Phi subfamilies had the highest enrichment of these elements. Together with the gene-family classification and duplication analysis, the promoter profiles provide a comparative view of the genomic organization and potential regulatory features of GST genes in the four legume species.

The study also examined expression patterns under different stress conditions and across biological transitions. The researchers reported responses to abiotic and biotic stresses, as well as expression patterns associated with grazing recovery, nodule formation and light induction. These analyses revealed distinctive response patterns within the legume GST superfamily, although the supplied study summary does not report the effect size, uncertainty or statistical performance of individual expression changes.

By combining whole-genome gene identification, phylogeny, analysis of duplication, promoter inspection and expression profiling, the study assembled a genomic resource for GST genes in four representative legumes. The authors described the results as a foundation for further research into genetic improvement of stress tolerance in leguminous crops and forage plants. That application remains a stated research direction rather than a demonstrated outcome of the present analysis.

Subject of Research: Genome-wide analysis of GST genes and stress-associated expression in four legume species

Article Title: Genome-wide identification and expression characteristics under stress of the Glutathione S-transferase supergene family in Leguminosae

Article References: Wang, L., Ma, Q., Hu, Y., Liu, C., Wang, H., Li, Y., Gao, S., Guo, R., Jia, S., Duan, Q., Li, D., & Yang, X. (2026). Genome-wide identification and expression characteristics under stress of the Glutathione S-transferase supergene family in Leguminosae. BMC Plant Biology. https://doi.org/10.1186/s12870-026-09802-1

Image Credits: AI Generated

DOI: 10.1186/s12870-026-09802-1

Keywords: legume genomics, glutathione S-transferase, gene duplication, plant stress responses, promoter analysis, soybean, alfalfa, peanut, barrel medic, plant evolution, Genome-wide, identification