Physical approaches for plant and fungi biomechanics

Abstract

I will give in this talk several examples where experimental techniques from physics and especially microfabrication using soft lithography can help understanding biophysical phenomena in plant and fungi.
 In a first part, I will show how the study of simple evaporative devices made of elastomeric microfluidics channels help us to better understand plant leaves geometrical characteristics [1].
 In a second part I will present a work done on spores ejection in ferns sporangia. A catapult mechanism ejects the spores using negative pressures down to -100 bar [2]. We have described the complex fast dynamics of the annulus and the collective dynamics of nucleation of cavitation bubbles. I will then show how we studied the same phenomenon in artificial devices made in hydrogels by microfabrication. This allowed us to better understand the cavitation propagation.
 In a last part, I will present briefly a new ongoing collaboration with the Arkowitz team in iBV on filamental growth in yeast-like fungi. Here we also use soft lithography microfabrication techniques in order to study the forces at play during growth and invasion.
 
 [1] Noblin, X., Mahadevan, L., Coomaraswamy, I. A., Weitz, D. A., Holbrook, N. M. and Zwieniecki, M. A. "Optimal vein density in artificial and real leaves," PNAS,  105, 27 pp. 9140-9144. (2008)
 [2] Noblin, X., Rojas, N., Westbrook, J., Llorens, C., Argentina, M., Dumais, J., The fern sporangium: a unique catapult. SCIENCE  335, 6074, p.1322 (2012)