Genome-Wide Identification of the Gene Family and the Function of Under Salt Stress.

A comprehensive genome-wide identification of SET-domain-containing genes in (tomato) has revealed 46 members. Phylogenetic analysis showed that these genes, along with those from and , are divided into five subfamilies, with Subfamilies II and V being the largest. Motif and domain analyses identified 15 conserved motifs and revealed the presence of pre-SET and post-SET domains in several genes, suggesting functional diversification. Gene structure analysis further demonstrated variation in exon-intron organization, likely contributing to differential gene regulation. Promoter analysis identified -acting elements related to light responsiveness, plant growth, hormones, and stress, implicating genes in various biological processes. RNA-seq and qRT-PCR data revealed distinct expression patterns of genes under salt stress, with several genes showing significant upregulation, indicating their potential role in stress tolerance. In particular, silencing using VIGS reduced tomato's tolerance to salt stress, leading to higher lipid peroxidation, reduced antioxidant enzyme activity, and decreased proline content, further confirming its critical role in salt stress response. These findings provide valuable insights into the functional diversity, evolutionary history, and stress-related roles of SET domain genes in tomato, with potential applications for crop improvement strategies.