A research team led by Professor Jae-Hoon Jung from the Department of Biological Sciences has revealed that liquid–liquid phase separation (LLPS) in plant cells is delicately and reversibly regulated by changes in ambient temperature and that this phenomenon serves as a key mechanism for determining the timing of flowering in plants. This study was conducted in collaboration with Professor Pil Joon Seo’s group in the Department of Chemistry at Seoul National University (first author Dr. Hong Gil Lee) and Professor Jong-Chan Lee’s group in the Department of New Biology at DGIST (first author Ph.D. candidate Jinkwang Kim).

The team discovered that GIGANTEA (GI), a core regulator of flowering, undergoes reversible phase separation depending on temperature. At lower temperatures (22°C), GI forms inactive nuclear condensates inside the plant cell nucleus. At higher temperatures (28°C), these condensates dissolve, and GI becomes dispersed and activated. Notably, GI in its dispersed state—rather than in condensates—binds to the floral repressor SVP and promotes its degradation, thereby accelerating flowering under warm temperature conditions.
Furthermore, the researchers found that FKF1, a blue-light photoreceptor, selectively binds to the intrinsically disordered region (IDR) of GI, enabling the temperature-specific and reversible dissolution of GI condensates at elevated temperatures, thereby activating GI.

Previously, in a 2020 Nature paper, Professor Jung’s team identified temperature-dependent phase separation of the ELF3 protein as a plant-specific temperature-sensing mechanism. In this study, they demonstrated that phase separation of a key flowering regulator is a central mechanism enabling plants to fine-tune their development in response to even slight changes in air temperature. This work highlights the potential of developing precision control technologies for plant growth and development based on intracellular phase separation, which could play a crucial role in ensuring stable food production and enhancing agricultural competitiveness under climate change.
This research was supported by the National Research Foundation of Korea (NRF) and the Rural Development Administration, and was published online in Nature Plants on July 4th.

※ Paper Title: High-temperature-induced FKF1 accumulation promotes flowering through the dispersion of GI and degradation of SVP
※ DOI: https://doi.org/10.1038/s41477-025-02019-4
※ Authors: Prof. Hong Gil Lee (first author, SNU), Ph.D. candidate Jinkwang Kim (first author, DGIST). Ph.D. candidate Kyung-Ho Park (first author, SKKU Department of Biological Sciences), researcher Sol-Bi Kim (co-author, SKKU Department of Biological Sciences), Prof. Jae-Hoon Jung (corresponding author, SKKU Department of Biological Sciences), Prof. Jong-Chan Lee (corresponding author, DGIST), Prof. Pil Joon Seo (corresponding author, SNU)

Figure. Working model of FKF1–GI in temperature-responsive flowering