Combination of Transcriptome sequencing and iTRAQ proteome reveal the molecular mechanisms determining petal shape in Herbaceous Peony (Paeonia lactiflora Pall.).

The molecular mechanisms controlling petal shape in a herbaceous peony, Paeonia lactiflora Pall., a popular high-grade cut flower worldwide, remain unclear. Here, we selected inner and outer petals from P. lactiflora 'ZiFengyu' with an anemone type as the study object. Using transcriptome sequencing and isobaric tags for relative and absolute quantitation (iTRAQ) proteome, 979 differentially expressed genes and 266 differentially expressed proteins were detected within the inner and outer petals. Of these, the present study identified a key gene APETALA2 that regulates flower shape development. In addition, we obtained a 1935 bp full-length cDNA sequence of APETALA2 by rapid amplification of cDNA ends amplification (RACE). Through further validation using quantitative real time polymerase chain reaction (qRT-PCR) and western blot analysis, APETALA2 showed a markedly higher expression in outer than that in inner petals. Therefore, the present study indicates that the increased expression of APETALA2 contributes to the formation of petals in P. lactiflora .