Genome-wide analysis of TCP gene family in Osmanthus fragrans reveals a class I gene OfTCP13 modulate leaf morphology

Osmanthus fragrans is a woody perennial that is cultivated in most Asia areas and widely employed for gardening and landscaping purposes. In addition to its distinctive fragrance, there has been a growing interest in the variation of O. fragrans leaf shapes. However, there are limited reports regarding the role of TCP genes regulating leaf morphology in O. fragrans . In this study, a total of 39 TCP members were identified at the genome level, and the sequence characteristics and tissue expression of class I TCP genes were analyzed. The highest expression gene OfTCP13 cloned from O. fragrans cultivar 'Yanhonggui' and transferred into tobacco plants. Moreover, the OfTCP13 protein was found to be localized in the nucleus and lacked transcriptional activation activity. Compared with wild-type (WT) plants, overexpression of OfTCP13 significantly influenced the leaf morphology of tobacco plants, resulting in significantly greater leaf thickness and blade length-to-width ratio than WT plants. Furthermore, the cross-section of the transgenic tobacco plants exhibited mesophyll cell number increased relative to WT plants, suggesting that OfTCP13 may regulate leaf morphology through promoting mesophyll cell number. Together, our results can provide a valuable insight into the improvement of diversity of leaf morphology in O. fragrans . Citation: Zheng Z, Xu Q, Tang J, Chen P, Hu Z, et al. 2023. Genome-wide analysis of TCP gene family in Osmanthus fragrans reveals a class I gene OfTCP13 modulate leaf morphology. Ornamental Plant Research 3:15 https://doi.org/10.48130/OPR-2023-0015