Mechanical Stress Induces Remodeling of Vascular Networks in Growing Leaves
Fig 4
Stretching leaves: Tracing of the venation pattern throughout growth.
The transparent drops visible in panel (A) are epoxy glue. The tensile force was applied between these points. The distance between the stretching points is 3.5mm on day 1 and 9.3mm on day 15. In panel (a) we plot the locations of the stretched (right) and freely-grown (left) regions in the leaf on day 1. A close up shows that the freely-grown region grew by isotropic expansion, while the stretched region grew anisotropically (note the different scales for day 1 and day 15). This is confirmed by superimposing the rescaled venation patterns from day 1 (red) and day 15 (blue). (B) Quantification of the large scale anisotropy of growth: The elongation of two perpendicular segments in each region. The endpoints of each segments are marked by colored points in panel (A), and the same color code is used in panel (B). The length of each segment is normalized by its initial value.