Figure 2
Schematic illustrations of the postulated (a) fibril reorientation and (b) fibril slippage mechanisms. (a) In the fibril reorientation mechanism it is postulated that microfibrils within the cell wall reorient toward the longitudinal axis when the wall undergoes plastic deformation in the longitudinal direction during elongation growth. If the microfibrils are predominately oriented in the direction shown (right-handed helix), a displacement vector, d, will be produced by the fibril reorientation. The displacement vector adds a clockwise rotation to the elongation and produces left-handed helical growth. (b) In certain situations, it is postulated that the microfibrils slide passed each other along their direction of orientation, i.e. fibril slippage. In this case, the displacement vector, d, adds a counter-clockwise rotation to the elongation and produces right-handed helical growth.
