Genome Editing Technology Modifies Lisianthus to Suitable Bushy Form for Pot Plants

A research group led by Professor Takashi Nakatsuka of the Faculty of Agriculture at Shizuoka University, in collaboration with Tokushima University, Tokyo University of Science, the National Agriculture and Food Research Organization, and Miyoshi Co., Ltd., has succeeded in modifying the growth habit of lisianthus through genome editing.

Key Research Points:

■ Successful introduction of mutations using genome editing technology in lisianthus, a major cut flower.

■ Creation of lisianthus genetic resources with a compact and voluminous growth habit.

■ Proposal of a new breeding technology to broaden the applications of cut flowers.

We have developed lisianthus suitable for appreciation as pot plants and bedding plants. Lisianthus is primarily a cut flower suitable for bouquets and vases. By using genome editing technology to disrupt the function of strigolactone, a hormone that suppresses branching in plants, we induced a reduction in plant height and an increase in the number of branches, which in turn increased the number of flowers. We have succeeded in creating a compact and voluminous growth habit that has been rarely seen in lisianthus until now.

The research results obtained in this study are expected to contribute to the creation of useful genetic resources for further practical variety development, allowing lisianthus to join the ranks of new commercial products for pot plants and bedding plants. Furthermore, it has been shown that strigolactone deficiency is an effective technology for converting the growth habit of ornamental flower species to dwarf and highly branched forms without altering their growth characteristics.

These research findings were published in the open-access international journal "Plant Cell Reports" by Springer Nature on June 3, 2026.

Researcher Comments:

Takashi Nakatsuka, Professor, Faculty of Agriculture, Shizuoka University

It took many years from envisioning the use of branching-suppressing hormone mutants in ornamental flowers to creating strigolactone mutants and evaluating their traits. Thanks to the many collaborators, we have succeeded in creating useful genetic resources with dwarfism and multi-branching characteristics.

Background of the Research:

Lisianthus is a major cut flower with a domestic production value of 13.3 billion yen, used for bridal arrangements and decorations. Varieties with diverse flower colors and shapes have been developed, making it a popular ornamental flower species. Lisianthus has a single main stem that elongates, bearing 3 to 5 flowers at its tip. Therefore, it has a suitable growth habit for arrangements such as bouquets. However, for use as pot plants or bedding plants, it lacks volume in its growth habit, and only a few pot-use varieties of lisianthus have been bred.

Strigolactone is a plant hormone that suppresses branching. In rice, strigolactone-deficient mutants are known to cause phenotypes with increased tillering and reduced plant height. Therefore, we hypothesized that by creating strigolactone mutants in lisianthus, a cut flower species, it might be possible to modify its growth habit to be more voluminous. In this study, we created strigolactone-deficient mutants of lisianthus using genome editing technology and evaluated their phenotypes.

Research Results:

We isolated the carotenoid cleavage dioxygenase 8 (CCD8) gene, one of the strigolactone biosynthesis enzymes, from lisianthus and generated transgenic plants for genome editing. Four transformants were obtained, and mutations in the CCD8 gene were confirmed in three of these lines. In the progeny of these lines, obtained after self-pollination, individuals in which the CCD8 gene mutation was inherited in a homozygous state showed a 40% reduction in plant height and a 4.5-fold increase in the number of branches compared to the wild type. Furthermore, due to the change in growth habit, the number of flowers per plant increased 1.7-fold, and the flowering period was extended due to continuous blooming.

Future Prospects and Ripple Effects:

Among the CCD8 genome-edited lisianthus lines obtained in this study, individuals lacking foreign genes (null segregants) have been obtained. These individuals inherit only the CCD8 mutation and exhibit dwarf and multi-branching phenotypes. Since null segregants are not subject to regulations for genetically modified organisms, they are important characteristics for breeding applications. In the future, by using genome editing technology to create strigolactone mutants in lisianthus lines with diverse flower colors and shapes, we will produce more practical and useful genetic resources. While the applications of ornamental flowers have traditionally depended on the characteristics of the plant species, this breeding technology, which transforms cut flowers into pot plants and bedding plants, is expected to lead to the creation of new genetic resources.

Publication Information:

Journal:

Plant Cell Reports (Springer Nature)

Article Title:

Engineering plant architecture in the ornamental species Eustoma grandiflorum by knockout of strigolactone biosynthesis

Authors:

Kana Yamaguchi, Eri Tomizawa, Noriko Kanematsu, Kimitoshi Sakaguchi, Takashi Kasai, Ryo Ebisawa, Akihiro Hasumi, Kyoko Kawakatsu, Yuriko Osakabe, Keishi Osakabe, Takashi Nakatsuka

DOI: https://doi.org/10.1007/s00299-026-03867-w

Research Funding:

G-7 Scholarship Foundation Research and Development Grant Program (Agriculture and Fisheries Fields)

Japan Society for the Promotion of Science (JSPS) Grants-in-Aid for Scientific Research JP16H06279 (Advanced Genomics Support)

Glossary:

Genome Editing:

A technique where genomic DNA is cut at a target sequence, and mutations are introduced during the repair process of the cut DNA. The genome editing enzyme CRISPR-Cas9 acts as scissors to cut the target sequence, and was used in this research.

Strigolactone:

A plant hormone that suppresses the growth of axillary buds in the above-ground parts and inhibits branching. It is also secreted from roots and acts as a symbiotic signal for parasitic weeds.

Null Segregant:

An individual that, after being crossed with an organism into which foreign genes such as Cas9 and guide RNA were introduced through genetic modification, inherits only the mutation in the target gene from genome editing and no longer possesses the introduced foreign genes. Since foreign genes are absent, it is not subject to regulations for genetically modified organisms. Therefore, with appropriate evaluation and procedures, it can be handled as a non-genetically modified organism.