Ikoma, Japan—In an era where climate change threatens food security, scientists worldwide are searching for reliable ways to improve crop production. Extreme weather and shifting seasonal patterns can disrupt traditional agricultural cycles, making technologies that regulate the timing of plant growth invaluable for farmers worldwide.
Plant growth and development are dependent on many factors such as the environment, photoperiod, and genetics. Flowering is an important event in a plant's life cycle, and in many species, a period of cold exposure (or vernalization) is required before flowering in the spring. Once flowering begins, plants redirect nutrients from their leaves to seed production, reducing the nutritional value of leafy crops. While scientists understand many aspects of this process, mechanisms that can naturally pause or reverse this phase of preparation for flowering (devernalization) remain largely unexplored.
Against this backdrop, a research team led by Assistant Professor Makoto Shirakawa of Nara Institute of Science and Technology (NAIST), Japan, has been investigating the molecular basis of devernalization. They identified a new class of small molecules called devernalizers (DVRs), capable of inducing devernalization without the requirement of heat treatment in the model organism Arabidopsis thaliana. Their findings were published in Volume 8 of Communications Biology on January 22, 2025. This work was co-authored by Nana Otsuka, Ryoya Yamaguchi, Hikaru Sawa, Nobutoshi Yamaguchi, and Toshiro Ito from NAIST; Naoya Kadofusa, Nanako Kato, and Ayato Sato from Nagoya University; and Yasuyuki Nomura and Atsushi J. Nagano from Ryukoku University.
The researchers screened over 16,000 chemical compounds and discovered five DVRs that reactivated the expression of the FLOWERING LOCUS C gene, a key suppressor of flowering. By minimizing specific dynamic modifications to the plant's genes, these DVRs could delay flowering even after induced vernalization. Notably, three of these DVRs shared two critical structural features—a hydantoin-like region and a spiro-like carbon—which were found to be essential for the devernalizing effect.
Furthermore, the team identified a sixth DVR compound—named DVR06—which was structurally simpler yet retained the above-mentioned key features. Experimental results showed that plants treated with DVR06 exhibited delayed flowering without adverse side effects. A genome-wide analysis revealed that DVR06 affected a more specific set of genes compared to heat-induced devernalization, highlighting its potential for flowering regulation. "It was well known that applying heat treatment to plants in the field is both labor-intensive and costly. So, I was really excited when we found out that DVR06 had a more specific effect than heat treatment. This was the moment when all the time we had spent on screening finally paid off!" shares Shirakawa.
The discovery of DVR06 and its mechanisms could pave the way for new agricultural technologies that allow farmers to effectively regulate flowering times. By delaying flowering, leafy crops may maintain their nutritional quality for longer periods, increasing yields and reducing wastage. The research team aims to improve the efficacy of DVRs, as Ito remarks: "We will conduct further research to change the structure of DVRs to develop compounds with greater activity and specificity. We expect the results of these studies to lead to the development of new technologies for stable food production under a fluctuating global environment."
