iTRAQ-based quantitative proteomics of cultivated Pseudostellaria heterophylla and its wild type / 药学学报

ABSTRACT

This work was designed to investigate proteins differentially expressed in cultivated Pseudostellaria heterophylla and its wild type using iTRAQ proteomics approach. The extracted proteins were digested using FASP method and identified by iTRAQ coupled with LC-MS/MS technology and then analyzed by Protein Pilot 5.0 search engine. Proteins differentially expressed were searched through comparison of relatively quantified proteins. The analysis was conducted using GO (gene ontology), KEGG and STRING. A total of 3 775 proteins were detected, among them, 3 676 proteins can be quantified, of which 127 proteins were up-regulated and 205 were down-regulated in cultivated Pseudostellaria heterophylla. We found 71 significantly differentially expressed proteins for further analysis. These proteins were classified into nine categoriesheat shock proteins, transferases, oxidoreductases, lyases, isomerases, ligases, hydrolases, tubulin and translocases. The results indicated that the carbohydrate and cellular amino acids metabolism of cultivated Pseudostellaria heterophylla were weaker than its wild type and its ability of responding to stress was much stronger. GWD1, PHS1, GBE1, PGM, and BAM1 are the important proteins to regulate sucrose; metE and CYS are the key proteins that regulate amino acids in cultivated and wild Pseudostellaria heterophylla. This will provide the basic information for exploring the cause of secondary metabolites differences in different ecotype of Pseudostellaria heterophylla and the protein mechanism of its quality formation.