Laboratories and faculty

Plant Growth Regulation

Outline of Research and Education

Plants continuously produce organs throughout their life. This feature renders them distinct from animals, in which organ formation ceases soon after embryogenesis. We aim to understand the mechanisms of DNA polyploidization, stress response and stem cell maintenance that support sustained plant growth under changing environments. Our study will contribute to the development of technologies to increase plant biomass and food production.

Major Research Topics

Mechanisms for induction of DNA polyploidization

In many plant species, cells start DNA polyploidization after the cessation of cell division. DNA polyploidization causes enlargement of individual cells and organs; thus, it greatly contributes to plant biomass production. We are studying how cell cycle- and chromatin-level regulation is involved in the induction of DNA polyploidization, and developing technologies to enhance DNA polyploidization in crops and woody plants, aiming to increase food and biomass production.

Plant growth regulation in response to abiotic stress

Plant growth is usually inhibited under stressful conditions because plants need to use energy for coping with stress, rather than for organ growth. We have recently identified the signaling cascade that triggers cell cycle arrest in response to DNA damage and heat stress. We are studying how this cascade orchestrates expression of G2/M-specific genes and generating stress-tolerant plants by modifying the signaling components.

Maintenance of plant stem cells

Any plant has a long life span if the developmental program is optimized, and continues to grow throughout its life. This feature is derived from persistent proliferation of pluripotent stem cells scattered throughout the plant body. We are studying the molecular mechanisms of how stem cells are maintained and replenished in tissues to understand plant vitality.

Fig. 1
Fig. 1 Increase of plant biomass by enhancing DNA polyploidization.
Change in chromatin structure as well as in cell cycle progression is essential for induction of DNA polyploidization.
Fig. 2
Fig. 2  A signaling module inducing cell cycle arrest in response to abiotic stresses.
Transcription factors MYB3R3/5 cause G2 arrest in response to DNA damage and heat stress. Suppression of the signaling cascade will enable us to generate stress-tolerant plants.
Fig. 3
Fig. 3 Stem cell maintenance in the root tip.
Stem cell death, which occurs in response to DNA stress, is accompanied with division of a neighboring QC cell, thereby replenishing stem cells.

References

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