Contributing to the future of the Earth and society through the control of genetic information in chloroplasts and mitochondria
Photosynthesis, the gateway to energy for the Earth's ecosystem, including humans, is carried out by chloroplasts in plant cells. In addition, mitochondria play a role in part of the respiration and metabolism that support all plant cells and life cycles. Chloroplasts and mitochondria, two vital organelles in plant cells, carry their own small genomes, separate from the cell’s nuclear DNA. These organelle genomes encode many of the key components needed for photosynthesis, respiration, and other metabolic processes. However, because it has been more difficult to artificially modify organelle genomes than nuclear genomes, basic understanding of them and the development of applications such as new plant breeding that is expected by modifying and improving organelle genomes have been delayed. Together with many collaborators and students, I have succeeded in the world's first genome editing of plant mitochondria in 2019 and chloroplasts in 2021. Based on these technologies, we are currently working on further technological improvement, basic research, application development, and social implementation that will lead to improved plant breeding. With many collaborators, our goal now is to build and elevate the organelle-genome research field into one of Japan’s signature strengths.
Educational approach
Acquiring scientific attitude/execution/adaptability through exploration of the frontiers of knowledge
I teach courses such as Cell Biology for undergraduates and Advanced Plant Molecular Genetics for graduate students, providing the fundamentals that form the basis of Plant Genetics and Breeding Science. Undergraduate and graduate students assigned to the laboratory are encouraged to engage in research at the forefront of the field and to tackle puzzles that involve world-first discoveries, respectively. Research and experimental activities—including clarifying the boundaries of knowledge through information gathering, articulating unknowns and questions, understanding, designing, and mastering methods of investigation, carrying out verification, refining and repeating experimental results, developing interpretations by integrating external information, and disseminating knowledge through presentations and publications—are all challenging, labor-intensive tasks. However, I believe that this very process constitutes an essential form of education that directly connects to activities and success in the real world. Through these “research and experimental activities,” our goal is for our graduates to acquire a scientific attitude and the ability to perform and respond to reality, which will be useful no matter what field they enter.
Vision for industry-academia collaboration
Making the World a Better Place by Regulating Plant Organelle Genomes
Although the organelle genome contains less than 1% of the genetic information of the nuclear genome, it encodes many key factors for chloroplast and mitochondrial functions. Although the organelle genome has not been utilized due to the difficulty of modification, it has high potential through improvement. Modification of the chloroplast genome will lead to improvement of photosynthesis/growth capacity/yield, improvement of CO2 absorption and assimilation capacity, reduction of fertilizer use, and labor saving of plants/crops.
In addition, the cytoplasmic male sterility gene in the mitochondrial genome code has been used for seed production of F1 varieties used around the world without the underlying mechanisms being understood, but our technology is now making a significant contribution to the ongoing elucidation of its diverse molecular mechanisms. Genome editing technologies, due to their precision and minimal off-target effects, as well as favorable societal acceptance and regulatory conditions, are increasingly being implemented in many countries, making them a promising avenue for applied utilization and development. I believe that “developed technologies have value only when they are used,” and therefore I aim to make a positive contribution to society and the future of the planet by contributing to the development of agricultural biotechnology and plant breeding.
