Genome-wide annotation and expression analysis of and transcriptional factor families reveal their involvement under cadmium stress in tomato ( L.).

The and transcription factors have been implicated in the regulation of gene expression during various physiological processes in plants, especially in plant stress responses. However, little information about the heavy metal-responsive and in tomato () is available. We performed a genome-wide investigation for these two TF families in and determined their role in cadmium (Cd) stress tolerance. Furthermore, ortholog analysis with the genome led to classifying and ortholog genes into nine and 11 clusters, respectively. The comparative phylogenetic analysis revealed duplication events and gene loss in and , which occurred during evolution both before and after the last common ancestor of the two species. Orthologous relationships are also supported by additional evidence, such as gene structure, conserved motif compositions, and protein-protein interaction networks for the majority of genes, suggesting their similar functions. A comprehensive transcriptomics analysis revealed that both and genes were differentially expressed in response to cadmium stress as compared with control plants. A gene ontology analysis revealed that most and are DNA-binding essential proteins that regulate gene expression positively and negatively. Analyses of interaction networks revealed that both and mediate networks implicated in several stress-signaling pathways. The findings of this work may help us to comprehend the intricate transcriptional control of and genes and identify potential stress-responsive genes relevant to tomato genetic improvement. Moreover, identifying heavy metal stress-responsive and genes in . will provide fundamental insights for developing new heavy metal stress-tolerant varieties of tomato crops.