Exploring transcriptomic dynamics in petal development of the one-day flower species, Japanese morning glory (Ipomoea nil)

The Japanese morning glory (Ipomoea nil) is a one-day flowering species and an annual vine plant originating from tropical America. It has uniquely developed as a representative horticultural plant in Japan, with a research history dating back to the early 1900s. Many studies have particularly focused on its flower petals. Due to the one-day blooming feature of the flower, extensive research has been conducted on flower opening and senescence. I. nil exhibits many mutants in petal color and shape, which have been used for studies on petal pigmentation and morphogenesis. In this study, to understand the broad characteristics of the flower petals, a temporal multi-sample transcriptome analysis on I. nil petals was performed. Flower petal samples were collected every three hours over three and a half days, from 72 hours before flowering to 12 hours after, with three biological replicates. This period spans stages from the bud phase through full bloom to the fully closed flower. In total, RNA was extracted from 87 samples across 29 time points and subjected to RNA-seq analysis. The Lasy-seq method was used for library preparation to reduce costs per sample. A database has been created from the obtained transcriptome data, which will serve as a useful tool for future studies on petal development and broader physiological phenomena in I. nil and other plant species.