Genome-wide identification, characterization, evolution, and expression pattern analyses of the typical thioredoxin gene family in wheat ( Triticum aestivum L.).

Typical thioredoxin (TRX) plays an important role in maintaining redox balance in plants. However, the typical genes in wheat still need to be comprehensively and deeply studied. In this research, a total of 48 typical genes belonging to eight subtypes were identified a genome-wide search in wheat, and the gene structures, protein conserved motifs, and protein 3D structures of the same subtype were very similar. Evolutionary analysis showed that there are two pairs of tandem duplication genes and 14 clusters of segmental duplication genes in typical family members; , , and had positive selection compared with the orthologs of their ancestral species; rice and maize have 11 and 13 orthologous typical with wheat, respectively. Gene Ontology (GO) analysis indicated that typical were involved in maintaining redox homeostasis in wheat cells. Estimation of ROS content, determination of antioxidant enzyme activity, and gene expression analysis in a line overexpressing one typical confirmed that plays an important role in maintaining redox balance in wheat. A predictive analysis of -acting elements in the promoter region showed that typical were extensively involved in various hormone metabolism and response processes to stress. The results predicted using public databases or verified using RT-qPCR show that typical were able to respond to biotic and abiotic stresses, and their expression in wheat was spatiotemporal. A total of 16 wheat proteins belonging to four different families interacting with typical TaTRXs were predicted. The above comprehensive analysis of typical genes can enrich our understanding of this gene family in wheat and provide valuable insights for further gene function research.