Research on plant hormones
for the production of pest-resistant
crops and the utilization of
plant defense response

Interest in dramatic changes occurring inside plants

I am a first-year master's student in the Graduate School of Media and Governance at Keio University, and a member of the Institute for Advanced Biosciences. I research the systematic understanding of plant hormone responses.

My grandfather and father loved gardening, so I have been around plants. When I learned about plants and animals in school, I was fascinated to discover that plants undergo drastic internal changes to adapt to environmental stress. Since then, I have been interested in cells.

Before university, I wanted to learn transcriptome analysis, a technology that captures the internal state of living organisms based on genetic information. After entering Keio University's Faculty of Environment and Information Studies, I joined the Institute for Advanced Biosciences. I joined the Nagano Plant Omics Group, which has a proven track record in transcriptome research, and began studying the transcriptional response of plants.

My skill set, knowledge, and awareness of what I did not know were constantly being updated. Making new discoveries motivated me to continue. Before I knew it, four years had passed. I felt that there was still much left to accomplish, and I did not want to stop. So I decided to pursue a master's degree in the Graduate School of Media and Governance with the goal of publishing an international paper. Furthermore, I could not envision how my experiences would be useful in society if I were to enter the workforce at that time.

Researching plant hormone balance that controls defensive responses using statistical methods

Plants cannot escape from predators as quickly as animals because they are rooted to the ground. Instead, they adapt to their surroundings by dramatically changing their physiological activity. These low-molecular-weight compounds that control such intense physiological changes are called plant hormones.

I am currently studying the responses of plants to salicylic acid (SA) and jasmonic acid (JA), two plant hormones that control defense responses. SA is synthesized in response to infection by parasitic fungi and produces antimicrobial substances while inhibiting parasites. Meanwhile, JA is synthesized in response to saprophytic fungi and insect pests, inducing infection resistance and anti-feeding substances. The hormonal signals of SA and JA interact in a highly complex manner. This is considered to be an important function that prevents excessive defensive responses while regulating defensive responses to diverse and changing external environments. Developing pest-resistant crops and utilizing plant immunity in the future requires understanding of the response to plant hormones.

I am focusing on the balance between SA and JA hormone signals. The balance between the two determines the outcome of SA/JA interactions and the resulting defense response. However, it remains unclear under what specific conditions that responses are induced. Previous studies on plant hormones have mainly involved experiments and analyses based on qualitative conditions resulting in many important findings. However, quantitative studies focusing on the combination of SA and JA or their respective concentrations are limited. Therefore, I am conducting large-scale hormone treatment and transcriptome analysis to systematically understand the gene expression response to the concentration of SA and JA and their combination.

While general plant physiology investigates the mechanisms of gene action individually, I take a bottom-up approach, starting with the overall picture. Unlike wet research, which focuses on quick experiments in large numbers, dry research is data-driven. Although I visit research sites and the Institute for Advanced Biosciences to conduct experiments, most of my research time is spent on online discussions and statistical analysis.

Developing biomarkers for estimating the response state of plant hormones

I am working on the development of transcriptomic biomarkers that enable quantitative estimation of plant hormone response states. Transcriptome analysis can comprehensively quantify the transcription levels of all genes and is widely used in current molecular biology. This transcriptomic data contains information on the current physiological state of cells and tissues, and is attracting attention as a means of accurately capturing the response state of plants.

However, the data is a complex matrix of genes and numerical values, and extracting useful information from it requires certain skills and knowledge. Therefore, it is not easy to grasp the response state. Therefore, I developed a biomarker that estimates the SA/JA response state level from transcriptome data simply and accurately. This enables retrospective analysis of past studies and, when combined with the transcriptome of wild plants, is expected to enable systematic analysis of the relationship between SA/JA responses and environmental variables. In addition, applying this to single-cell transcriptomics technology (scRNA-seq) could enable minute response states analysis at the single-cell level. Currently, I am applying this biomarker to various transcriptomic data to verify and analyze its usefulness and versatility.

SFC, where many life science researchers gather, discuss, and learn

The Institute for Advanced Biosciences is a research group covering a wide range of life science fields. Even within the field of life sciences, there are diverse angles, including differences in target organisms, fields, and approaches. The Institute has the facilities and technical expertise to handle a wide variety of organisms to respond to such diversity. This has enabled me to conduct research that combines transcriptome analysis and plant physiology flexibly.

Another distinctive feature compared to other graduate schools is that I can engage in discussions with students of the same age in different fields. Although our fields are different, there are some common elements in terms of methods and areas of study, which provide me with insights from other fields.

Furthermore, I also research fireflies with members of the Institute. I enjoy deep discussions and fieldwork with members who study different species, such as plants, tardigrades, and E. coli.

Presenting research both on and off campus to develop presentation skills

My research has provided me with awareness of how to explain things in an easy-to-understand manner. At first, I tended to explain my research using only technical terms, which often resulted in my audience not fully understanding. Through repeated presentations, I feel that I have gradually acquired the ability to organize my thoughts logically and communicate them clearly.

Furthermore, the SFC Academic Society provides research grants for academic presentations, and there are many opportunities to present research both within and outside the university, so I always feel fortunate.

At the 25th Keio SFC Academic Society held in March 2025, we were awarded the Silver Prize for "Analysis of phytohormone Dose-dependent responses and development of Biomarkers."
I intend to continue my research and preserve the knowledge I have gained about plant hormone responses for future generations. My first step will be to work hard to publish my findings in an international journal.

Introduction of Laboratory