You are here: Home News and Events Seminars Biology Fall 2018 How to grow 'Up': insights into the mechanisms of anisotropic growth in plants

How to grow 'Up': insights into the mechanisms of anisotropic growth in plants

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Speaker
Siobhan Braybrook University of California, Los Angeles
When
18 September 2018 from 4:00 PM to 5:00 PM
Where
Berg Auditorium, 100 Life Sciences Building
Host
Dept of Biology
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Live Stream:

http://live.libraries.psu.edu/Mediasite/Play/4ed1d940280d423da2bbc1d6f9d749811d

Abstract:

 Anisotropic growth in plant cells is canonically attributed to organized cellulose orientation within the cell wall. When arranged like 'hoops around a barrel' they restrict growth in width and promote elongation. In the Arabidopsis hypocotyl, following germination, anisotropic growth is not associated with such predicted cellulose orientation in the epidermis- instead the cortex cells display such organization. In a multi-cellular context, it appears that not all cells require the same kind of anisotropic information form their walls. The epidermis does display some elastic asymmetry at the cell level: the elongating axial walls are more elastic that the slowly growing transverse walls. When these two sets of anisotropic information are put together in a computational model- they hypocotyl grows faster and more anisotropically indicating a possible additive mechanism. An example of changing anisotropy, but not total growth, will be presented and the cellular mechanisms underlying this shift in anisotropy will be examined. The mechanisms include: cell wall mechanics, apoplastic pH, and proton pump activation.

Data on cell wall viscoelasticity will also be presented alongside a new AFM-based method of cell wall creep and stress relaxation experiments. The relation between wall elasticity, viscoelasticity, and growth will be discussed but not answered.