Genome-Wide Characterization of the () Zinc Finger Gene Family in and the Functional Analysis of in Shoot Gravitropism.

The plant-specific transcription factors (TFs) are vital for regulating plant growth and developmental processes. However, the characteristics and biological roles of the gene family in tomato () are still largely unexplored. In this study, 17 genes were identified in the tomato genome and classified into seven subgroups according to the evolutionary relationships of IDD proteins. Analysis of exon-intron structures and conserved motifs reflected the evolutionary conservation of in tomato. Collinearity analysis revealed that segmental duplication promoted the expansion of the family. Ka/Ks analysis indicated that gene orthologs experienced predominantly purifying selection throughout evolution. The analysis of -acting elements revealed that the promoters of genes contain numerous elements associated with light, plant hormones, and abiotic stresses. The RNA-seq data and qRT-PCR experimental results showed that the genes exhibited tissue-specific expression. Additionally, Group A members from and rice are known to play a role in regulating plant shoot gravitropism. QRT-PCR analysis confirmed that the expression level of in Group A was high in the hypocotyls and stems. Subcellular localization demonstrated that the SlIDD15 protein was localized in the nucleus. Surprisingly, the loss-of-function of by CRISPR/Cas9 gene editing technology did not display obvious gravitropic response defects, implying the existence of functional redundant factors within . Taken together, this study offers foundational insights into the tomato gene family and serves as a valuable guide for exploring their molecular mechanisms in greater detail.