Document Type
Article
Department
Physics (HMC)
Publication Date
10-2012
Abstract
We study the primary root growth of wild-type Medicago truncatula plants in heterogeneous environments using 3D time-lapse imaging. The growth medium is a transparent hydrogel consisting of a stiff lower layer and a compliant upper layer. We find that the roots deform into a helical shape just above the gel layer interface before penetrating into the lower layer. This geometry is interpreted as a combination of growth-induced mechanical buckling modulated by the growth medium and a simultaneous twisting near the root tip. We study the helical morphology as the modulus of the upper gel layer is varied and demonstrate that the size of the deformation varies with gel stiffness as expected by a mathematical model based on the theory of buckled rods. Moreover, we show that plant-to-plant variations can be accounted for by biomechanically plausible values of the model parameters.
Rights Information
© 2012 Silverberg, Noar, et al.
Terms of Use & License Information
DOI
10.1073/pnas.1209287109
Recommended Citation
J. L. Silverberg, R. N. Noar, M. Packer, M. Harrison, I. Cohen, C. Henley, S. J. Gerbode, “3D imaging and mechanical modeling of helical buckling in Medicago truncatula plant roots” Proc. Nat. Acad. Sci. 109, 16794 (2012). doi: 10.1073/pnas.1209287109
Comments
This article is also available from the Proceedings of the National Academy of Sciences website at http://dx.doi.org/10.1073/pnas.1209287109.