Xiaomin Liu (Thomas Greb's Laboratory, Center for Organismal Studies, Heidelberg University, Heidelberg, Germany)

2023. 11. 29 (Wed) 15:00 ~ 16:00

Conference Room (111) Myodaiji Campus

Miyo Morita(Terao), Division of Plant Environmental Responses (7556)

Precise organization of growing structures is a fundamental process in developmental biology. In plants, radial growth is mediated by the cambium, a stem cell niche continuously producing xylem and phloem in a strictly bidirectional manner. While several intercellular signaling cascades have been identified to instruct tissue organization during radial growth, the role of mechanical forces in guiding cambium stem cell (CSC) activity in the rigid environment of the cambium is still unclear. Here, we combine anatomical analyses with a cell-based vertex model to investigate the nature of mechanical stress at the cell and tissue scale in radially growing plant organs. We find that the expression of MAP70-1, encoding a microtubule-associated protein, is associated with individual radial cell files in the cambium suggesting that it potentially reveals cambium-related stress patterns. Simulations using realistic cellular outlines of the radially growing hypocotyl reveal a distinct stress pattern with circumferential stresses in CSCs. Moreover, simulations generate cambium-derived cell files only when mechanical stress is used for instructing cell division orientation. Further supporting the predictive power of our cell-based model, in silico and in planta mechano-perturbation have the same effects on CSC’s division orientation. Our work underlines the significant role of mechanical forces in CSC regulation through self-emerging stress patterns upon cell proliferation in the context of a major plant growth process.

*This seminar will be held in English