PsFT, PsTFL1, and PsFD Are Involved in Regulating the Continuous Flowering of Tree Peony (Paeonia × lemoinei ‘High Noon’)

Abstract

Tree peonies are an economically important crop with flowers of high ornamental value. Most tree peony cultivars in gardens are once-flowering, and the continuous flowering (CF) trait has been revealed only in a few tree peony cultivars, such as ‘High Noon’ (‘HN’). However, the molecular mechanism underlying its CF remains unclear. Here, we demonstrated that PsTFL1 functions as a floral inhibitor via the ectopic expression of PsTFL1 in transgenic Arabidopsis thaliana plants. Our findings suggest that PsFT and PsTFL1 interact with PsFD, and the detected interactions may occur in the nucleus. Compared with the non-CF variety, the gene expression patterns of PsFT, PsTFL1, and PsFD during the flower development indicate that these three genes may be related to the CF habit in tree peony ‘HN’. These findings will aid future investigations of CF behavior and promote the breeding of tree peonies and other perennial woody plants.