Plant Stem Cell Regulation and Floral Patterning

Professor: ITO Toshiro
Associate Professor: YAMAGUCHI Nobutoshi
Assistant Professor: WADA Yuko; Feng Yihong
Labs HP: https://bsw3.naist.jp/ito/

記事アイコン NAIST Edge BIO（0008、0033）

Outline of Research and Education

We are interested in the holistic view of gene regulation in plant reproduction, which leads to developmental robustness and coordination. We explore signaling and epigenetic control in stem cell maintenance, environmental response and fertilization. To reveal the molecular mechanisms, we use Arabidopsis as a model plant for genetic, reverse-genetic, biochemical and genomics approaches, as well as Brassicas and rice to study the conservation and diversification. Our students work at the frontiers of plant molecular genetics, developing their research, presentation and writing skills.

Major Research Topics

Proliferation, differentiation and senescence of floral stem cells

Flowers originate from self-renewing pluripotent stem cells in the floral meristems (Fig.1). In flower development, the stem cell activity is terminated in multistep pathways mediated by multiple transcription factors. The proliferation, differentiation and senescence of stem cells are regulated by a well-coordinated interplay of phytohormone signaling and epigenetic regulation, leading to spatiotemporal-specific gene regulation. We study downstream cascades of the key transcription factors controlling stem cell termination, flower organogenesis and senescence (Fig. 2). Through the integration of imaging, mathematical, and synthetic biology approaches, we aim to understand the principles of floral stem cell control at the molecular, cellular, and organismal levels.

Environmental response, memory and resetting in plants

Plants respond flexibly to environmental changes and regulate flowering to ensure reproductive success. Many plants induce flowering after prolonged exposure to low temperatures (vernalization), whereas this memory can be reset by transient high-temperature treatment. We aim to elucidate the molecular mechanisms by which plants perceive and store environmental information, modulate developmental programs accordingly, and reset such memory. In addition, we also aim to elucidate the flowering regulatory mechanisms mediated by vacuole localized protein. These studies will provide a conceptual framework for understanding the plasticity and robustness of plant developmental responses under fluctuating environments (Fig.3).

Epigenetic regulation in sexual reproduction

Seeds of Brassicaceae species are important resources for food and biofuel production. Seed size is determined by the antagonistic interactions between maternally and paternally derived genomes. We have identified genetic manipulations of parental factors that lead to increased seed size, a trait directly linked to yield improvement. We aim to elucidate the epigenetic mechanisms underlying these processes, including genomic imprinting and related regulatory pathways.