A highly efficient mesophyll protoplast isolation and PEG-mediated transient expression system in eggplant

•An efficient system for eggplant protoplast isolation was established.•An efficient transient transformation system for eggplant protoplast was developed.•The subcellular localization of several eggplant genes was verified using this system.•Bimolecular fluorescence complementation assay was identified by this system.•The transient transformation system was also suitable for dual-luciferase assays .