Genome-Wide Identification of Genes in Eggplant ( L.) Reveals Their Potential Role in Anthocyanin Accumulation on the Fruit Peel

Anthocyanins are ubiquitous pigments derived from the phenylpropanoid compound conferring red, purple and blue pigmentations to various organs of horticultural crops. The metabolism of flavonoids in the cytoplasm leads to the biosynthesis of anthocyanin, which is then conveyed to the vacuoles for storage by plant (). Although is important for transporting anthocyanin in plants, its identification and characterization in eggplant ( L.) remains obscure. In this study, a total of 40 genes were obtained in the eggplant genome and classified into seven distinct chief groups based on the evolutionary relationship with GST genes. The seven subgroups of eggplant GST genes () comprise: dehydroascorbate reductase (DHAR), elongation factor 1Bγ (EF1Bγ), Zeta (Z), Theta(T), Phi(F), Tau(U) and tetra-chlorohydroquinone dehalogenase TCHQD. The 40 genes were unevenly distributed throughout the 10 eggplant chromosomes and were predominantly located in the cytoplasm. Structural gene analysis showed similarity in exons and introns within a subgroup. Six pairs of both tandem and segmental duplications have been identified, making them the primary factors contributing to the evolution of the . Light-related cis-regulatory elements were dominant, followed by stress-related and hormone-responsive elements. The syntenic analysis of orthologous genes indicated that eggplant, Arabidopsis and tomato ( L.) counterpart genes seemed to be derived from a common ancestry. RNA-seq data analyses showed high expression of 13 SmGST genes with being glaringly upregulated on the peel of purple eggplant but showed no or low expression on eggplant varieties with green or white peel. Subsequently, had a strong positive correlation with anthocyanin content and with anthocyanin structural genes like ( = 0.9), ( = 0.85), ( = 0.82) and ( = 0.7). The suppression of through virus-induced gene silencing (VIGs) resulted in a decrease in anthocyanin on the infiltrated fruit surface. In a nutshell, results from this study established that has the potential of anthocyanin accumulation in eggplant peel and offers viable candidate genes for the improvement of purple eggplant. The comprehensive studies of the family genes provide the foundation for deciphering molecular investigations into the functional analysis of genes in eggplant.