Evaluation of Opaque-2 effects on popping characteristics using iTRAQ-based proteome profiles in popcorn

Popcorn is a special kind of maize that can easily become popcorn flake when heated under a given condition. However, its popping mechanism still remains unclear at present. Opaque2 (O2) was a central transcriptional factor that plays important roles during maize endosperm development. In order to validate whether O2 affects the popping-related traits, an o2 introgression into N04 inbred line was constructed. We found that the mutation of O2 reduced the popping rate of N04. In order to reveal the underlying mechanism of O2 involved in popping characteristics, the o2 introgression and popcorn inbred line N04 were used to perform proteomic analysis at three developmental stages of their kernels using the 8-plex iTRAQ reagents with three repetitions followed by 2D-LC–MS/MS. A total of 5184 proteins were found, and 1073 proteins of which showed dynamics change. KEGG enrichment analysis found that these dynamic changed proteins were significantly enriched in carbon metabolism, pyruvate metabolism, citrate cycle, fructose and mannose metabolism, starch and sucrose metabolism, and pentose phosphate pathway. A total of 16 differentially expressed protein regulated by O2 were identified. These results preliminary uncover the molecular mechanism of popping characteristics in popcorn.