Platycodon grandiflorum, commonly known as Doraji in Korea, has a wide range of pharmacologic properties, such as reducing adiposity and hyperlipidemia, and antiatherosclerotic effects. However, the mechanisms underlying these effects remain unclear. In order to profile proteins from the nodal segment, callus, root and shoot, high throughput proteome approach was executed in the present study. Two dimensional gels stained with CBB, a total of 84 differential expressed proteins were confirmed out of 839 protein spots using image analysis by Progenesis SameSpot software. Out of total differential expressed spots, 58 differential expressed protein spots (≥ 2-fold) were analyzed using MASCOT search engine according to the similarity of sequences with previously characterized proteins along with the UniProt database. Out of 58 differential expressed protein, 32 protein spots were up-regulated such as ribulose- 1,5-bisphosphate carboxylase, endoplasmic oxidoreductin-1, heat stress transcription factor A3, RNA pseudourine synthase 4, cysteine proteinase, GntR family transcriptional regulator, E3 xyloglucan 6-xylosyltransferase, while 26 differential protein spots were down-regulated such as L-ascorbate oxidase precursor, late embryogenesis abundant protein D-34, putative SCO1 protein, oxygen-evolving enhancer protein 3. However, frequency distribution of identified proteins using iProClass databases, and assignment by function based on gene ontology revealed that the identified proteins from the explants were mainly associated with the nucleic acid binding (17%), transferase activity (14%) and ion binding (12%). In that way, the exclusive protein profile may provide insight clues for better understanding the characteristics of proteins and metabolic activity in various explants of the economically important medicinal plant Platycodon grandiflorum.

Platycodon grandiflorum is a perennial flowering plant, known as Chinese bell flower, widespread in northeast Asia. The roots of this species are used for centuries to treat diseases, and have extensive pharmacological effects such as reducing adiposity, hyperlipidemia as well as anti-atherosclerotic disorder. In this study, systematical and targeting proteome analysis were executed from the 3, 4 and 5 months aged diploid and tetraploid roots of Platycodon grandiflorum and the proteins were separated by 2-DE and stained by CBB. In diploid roots, a total of 30 protein spots (≥ 2-fold) were analyzed using MASCOT search engine according to the similarity of sequences with previously characterized proteins along with the UniProt database. Among the 30 differentially expressed proteins, 21 proteins sopts were identified as up-regulated and 9 proteins were identified as down-regulated. In contrary, a total of 40 differentially expressed proteins were confirmed from tetraploid roots whereas 28 protein spots were confirmed as up-regulated and 12 proteins were identified as down-regulated. However, the differentially expressed proteins from diploid and tetraploid roots were classified into 12 and 14 possible functional categories respectively using Protein Information Resources. The results revealed that the identified proteins from diploid and tetraploid roots were mainly involved in oxidoreductase activity, nucleotide binding, transferase activity and catalytic activity in bellflower roots. In conclusion, the exclusive proteins from diploid and tetraploid roots may provide insight clues for better understanding the characteristics and functions of proteins and metabolic activity of Platycodon grandiflorum.