Genome-wide identification and characterization of laccase family members in eggplant (Solanum melongena L.).

Laccase, as a copper-containing polyphenol oxidase, primarily functions in the process of lignin, anthocyanin biosynthesis, and various abiotic/biotic stresses. In this study, forty-eight laccase members were identified in the eggplant genome. Only forty-two laccase genes from eggplant (SmLACs) were anchored unevenly in 12 chromosomes, the other six SmLACs were mapped on unanchored scaffolds. Phylogenetic analysis indicated that only twenty-five SmLACs were divided into six different groups on the basis of groups reported in Arabidopsis. Gene structure analysis revealed that the number of exons ranged from one to 13. Motif analysis revealed that SmLACs included six conserved motifs. In aspects of gene duplication analysis, twenty-one SmLACs were collinear with LAC genes from Arabidopsis, tomato or rice. Cis-regulatory elements analysis indicated many SmLACs may be involved in eggplant morphogenesis, flavonoid biosynthesis, diverse stresses and growth/development processes. Expression analysis further confirmed that a few SmLACs may function in vegetative and reproductive organs at different developmental stages and also in response to one or multiple stresses. This study would help to further understand and enrich the physiological function of the SmLAC gene family in eggplant, and may provide high-quality genetic resources for eggplant genetics and breeding.