RpNACs transcription factors coordinate leaf margin development in Rosa persica.

Leaf morphology plays a crucial role in photosynthetic efficiency, environmental adaptation, and stress tolerance. Most Rosa species produce odd-pinnate compound leaves, whereas Rosa persica is the only species with simple leaves. In the wild, a naturally occurring deep-lobed leaf variant resembling a near-compound leaf was identified, providing a unique model for studying leaf development in woody plants. In this study, we aimed to characterize the NAC transcription factor family in R. persica and to investigate their roles in leaf margin morphogenesis. The NAC gene family was comprehensively analyzed using various bioinformatic approaches, including physicochemical property characterization, collinearity analysis and phylogenetic analyses, etc. Furthermore, WGCNA and expression profiling allowed the identification of five RpNAC genes, whose functions were subsequently investigated through subcellular localization, transcriptional activation assays, and heterologous overexpression in Arabidopsis thaliana. Candidate RpNAC proteins were nuclear-localized and exhibited transcriptional activation. Overexpression of RpNAP1 and RpNAC090.2 in Arabidopsis led to wavy leaf margins, increased leaf width, and enhanced chlorophyll content, indicating their important roles in leaf morphology and potential involvement in plant photosynthesis. These findings provide novel insights into the mechanism controlling leaf margin development in Rosa species and may facilitate targeted breeding of ornamental and stress-resilient traits.