Narrowing down the factors involved in the development of the structural colors of flowers

September 19, 2023

Structural colors refer to the colors that are expressed by the microscopic structure of the surface of a substance, and they are observed in various organisms such as insects and birds. Structural colors are also found in the petals of plants and are considered to contribute to the attraction of insects.

Hibiscus trionum (commonly known as the “Flower of an Hour”) is one of the plants that have a structural color on the petals. Flowers of H. trionum show purple in the center and light yellow on the outside. Purple is derived from anthocyanin pigments, but the epidermal cells of the petals that exhibit purple also have a fine uneven structure (ridges), and a structural color is also exhibited. It’s hard to see in the photo, but the angle is changed, the color changes.

A joint research group from the National Institute of Genetics, RIKEN CSRS, Tottori University, and the National Institute for Basic Biology conducted genome analysis and transcriptome analysis in H. trionum and successfully narrowed down the potential factors involved in the formation of the fine structure necessary for the development of structural color.
Key factors narrowed down:
- SHINE1: A transcription factor involved in cuticle formation in plants
- CUTIN SYNTHASE 2: A synthetic factor of cutin, one of the cuticular components
- CYP77A family gene: Also involved in the cutin synthesis

Since these factors are known to be involved in the formation of fine structures present in the petals of the model plant Arabidopsis thaliana, it is highly likely that they are also involved in the fine structure formation of H. trionum petals.

By starting with the narrowed down candidate factors, the team aims to identify the mechanism of fine structure formation and its evolution.

Original article
DNA Research doi: 10.1093/dnares/dsad019
S. Koshimizu, S. Masuda, A. Shibata, T. Ishii, K. Shirasu, A. Hoshino, M. Arita,
"Genome and transcriptome analyses reveal genes involved in the formation of fine ridges on petal epidermal cells in Hibiscus trionum".
Masanori Arita
Team Leader
Metabolome Informatics Research Team