ANisotropy, ADhesion and plant SPIral growth. – ANADSPI

In the 70's, the unicellular internode of acorticated characeae helped proving plant growth is pressure-driven and that growth and mechanical anisotropies are equal. The internode of the related corticated characeae is constituted by one giant cylindrical cell surounded by a layer of smaller elongated cells, the cortications; our project introduces this minimal multicellular model organism to quantitatify the interplay between turgor pressure, mechanical anisotropy and adhesion for spiral growth. A set-up to measure the elongation and rotation while controling the pressure inside the central cell will be mounted. “Constitutive laws”, estimated on the central cell, will be used to numerically extrapolate the elongation-rotation relation of corticated characeae and compare them to direct experiments thus precising the extent of the mechanical role of pressure on cell-wall growth. The respective roles of anisotropy and adhesion on rotation will be quantified using biochemical treatment.