iTRAQ-based quantitative proteomic analysis of transgenic and non-transgenic maize seeds
Weixiao Liu, Liang Li, Zhe Zhang, Mei Dong, Wujun Jin
Abstract
Proteomics provides a powerful approach to evaluate the unintended effects of transgenic crops. In this study, iTRAQ (isobaric tags for relative and absolute quantitation)-based quantitative proteomics was applied to estimate the differences in the proteomic profiles of maize seeds from 3 natural genotypic varieties and 4 genetically modified (GM) lines. Compared with their isogenic controls, there were 108, 69, 180 and 204 differentially expressed proteins (DEPs) in GM maize C0030.2.4, C0030.3.5, C0010.1.1 and C0010.3.1 seeds. Molecular functional classification showed that these DEPs were mainly involved in catalytic activity and binding. KEGG pathway annotation showed that most of these DEPs participated in metabolic pathways, the biosynthesis of secondary metabolites and microbial metabolism in diverse environments. In addition to the foreign protein EPSPS, 4 maize proteins were simultaneously identified as being differentially expressed among the 4 GM maize lines. Nevertheless, the regulation trends of these DEPs were not exactly consistent among the different GM maize lines. The data also showed that the differences in protein expression among the different natural genotypic varieties were greater than those caused by genetic modification. These results provide new information regarding the unintended effects of GM maize seeds through iTRAQ-based quantitative proteomic analysis.