Data from: Anisotropic growth is achieved through the additive mechanical effect of material anisotropy and elastic asymmetry

Fast directional growth is a necessity for the young seedling; after
germination, it needs to quickly penetrate the soil to begin its
autotrophic life. In most dicot plants, this rapid escape is due to the
anisotropic elongation of the hypocotyl, the columnar organ between the
root and the shoot meristems. Anisotropic growth is common in plant organs
and is canonically attributed to cell wall anisotropy produced by oriented
cellulose fibers. Recently, a mechanism based on asymmetric pectin-based
cell wall elasticity has been proposed. Here we present a harmonizing
model for anisotropic growth control in the dark-grown Arabidopsis
thaliana hypocotyl: basic anisotropic information is provided by cellulose
orientation) and additive anisotropic information is provided by
pectin-based elastic asymmetry in the epidermis. We quantitatively show
that hypocotyl elongation is anisotropic starting at germination. We
present experimental evidence for pectin biochemical differences and wall
mechanics providing important growth regulation in the hypocotyl. Lastly,
our in silico modelling experiments indicate an additive collaboration
between pectin biochemistry and cellulose orientation in promoting
anisotropic growth.