Floral fragrances are nature’s allure, enticing pollinators and helping plants adapt to environmental challenges. These scents, primarily generated in petals, consist of complex compounds such as terpenoids and benzenoids/phenylpropanoids, which hold immense ornamental and commercial value.
However, despite advances in identifying genes tied to volatile production, the cellular landscapes where these scents are made and the dynamic expression of related genes remain elusive. Bridging this knowledge gap requires a detailed exploration of the molecular and cellular organization of flower petals.
In a pioneering effort, researchers at Northwest A&F University have created the first-ever single-cell gene expression map of Prunus mume petals. Published in Horticulture Research, the study harnesses cutting-edge single-cell RNA sequencing to dissect gene activity in petals during budding and full-blooming stages. By identifying six distinct cell types, the research provides an unprecedented look into the molecular pathways driving floral scent biosynthesis and highlights their cellular precision.
This study focused on the petals of Prunus mume “Fenhong Zhusha,” a fragrant cultivar celebrated for its floral aroma. Researchers identified six key cell types, including epidermal and parenchyma cells as well as vascular tissues, each playing specialized roles in scent production.
The dynamic fragrance profile peaked at full bloom, with benzyl acetate and eugenol emerging as the dominant volatiles. Integrating single-cell and bulk RNA sequencing data, the team pinpointed 28 genes in the benzenoid/phenylpropanoid pathway, including PmPAL2, PmBAHD3, and PmEGS1, all exhibiting stage-specific expression.
Among the standout discoveries, PmBAHD3 was revealed as a multifunctional enzyme synthesizing both benzyl acetate and eugenol. These genes were predominantly active in epidermal and parenchyma cells, as confirmed through in situ hybridization. This cellular atlas not only clarifies the molecular mechanisms behind Prunus mume’s iconic fragrance but also offers fresh perspectives on spatially distinct metabolic processes in woody plant petals, setting the stage for new applications.
Dr. Tengxun Zhang, the study’s senior researcher, stated, “Our study reveals the cellular complexity of floral scent biosynthesis in Prunus mume. This research not only provides a detailed molecular roadmap but also unlocks new possibilities for advancing ornamental horticulture and the fragrance industry.”
The insights gained from this research have far-reaching applications. By targeting key genes like PmBAHD3 involved in scent biosynthesis, breeders could develop new aromatic cultivars with enhanced fragrance profiles. Additionally, the cellular atlas of Prunus mume serves as a model for studying scent production in other ornamental plants, offering transformative potential for the perfume and flavor industries.
This work represents a significant step toward sustainable cultivation and innovation in high-value plants, with implications for both science and industry.
Read the paper: Horticulture Research
Article source: TranSpread via Phys.org
Image: Plum blossom Prunus mume. Credit: Wikimedia
