Transcriptomic and proteomic analyses reveal changes in the metabolic pathways of Paeonia lactiflora petaloid stamens

Paeonia lactiflora or herbaceous peony, a famous traditional Chinese flower, is popular around the world for its cut flowers. Petaloid stamens are a common form of double flowers, but their underlying molecular mechanisms during development are still unclear. In this study, using the petaloid stamens of P. lactiflora 'Lian Tai' as research material, transcriptomic and proteomic analyses of flower buds at three developmental stages (stamen primordium, stamen primordium partly petaloid, and stamen primordium completely petaloid) were performed. A total of 81,971 unigenes were identified in the transcriptome, 8,288 proteins were identified in the proteome, and 8,152 genes and proteins were jointly identified in the transcriptome and proteome. GO annotation and KEGG enrichment analysis of differentially expressed proteins indicated that the metabolic pathways related to polysaccharides, carbohydrates, starch, sucrose, fructose, mannose, and photosynthesis were significantly enriched in petaloid stamens. After removing duplicates, 85 differentially expressed genes/proteins were identified in these metabolic pathways. These significantly enriched metabolic pathways and differentially expressed genes/proteins may play an important role in physiological and developmental processes associated with P. lactiflora petaloid stamens. This study provides additional transcriptomic and proteomic reference points for further exploring the molecular mechanisms during the development of P. lactiflora petaloid stamens.