Transformation-Induced Delphinidin Accumulation Inhibits Petal Expansion in Japanese Morning Glory
Mr. Huynh Ton-Phuc, a third-year doctoral student at the United Graduate School of Agricultural Sciences, had his research published in the peer-reviewed international journal “BMC Plant Biology” (Impact Factor: 5.6) in July 2026.
Delphinidin, a type of anthocyanin, is an important pigment responsible for blue coloration in plants. However, the function of the flavonoid 3′,5′-hydroxylase (F3′5′H) gene, which encodes a key enzyme in delphinidin biosynthesis, remains unclear, including its interactions with other genes related to anthocyanin biosynthesis.
This study examined whether Japanese morning glory (Ipomoea nil), which is easy to transform and has characteristics advantageous for anthocyanin biosynthesis research, can be used to analyze the function of F3′5′H. As a result, F3′5′H genes derived from lisianthus, pansy, and campanula were successfully expressed in transgenic I. nil and induced the accumulation of delphinidin. Surprisingly, flowers with petals that accumulated high concentrations of delphinidin failed to open. RNA-Seq analysis revealed significant changes in the expression of genes involved in stress responses, detoxification responses, and senescence in petals whose expansion was inhibited.
This study demonstrated that I. nil enables efficient functional analysis of F3′5′H genes. Although abnormal pigment accumulation has been reported to inhibit petal expansion in other plants, such as petunia and torenia, the differentially expressed genes associated with this inhibition have not been investigated. The findings of this study provide important insights into the mechanism by which pigments inhibit petal expansion.
■ Publication Information
Title: Ectopic expression of the flavonoid 3′,5′-hydroxylase gene in Ipomoea nil induces the accumulation of delphinidin-based anthocyanins in the petals and inhibits their opening
Authors: Ton-Phuc Huynh, Chihiro Motoyama, Hiroshi Oshima, Naoko Kozai, Nagisha Yamate, Fumio Hashimoto, Keiichi Shimizu
Journal: BMC Plant Biology
