Studying the influence of soil strength on root growth dynamics, Popova et al. document the mechanical and tropic responses of primary roots of maize (Zea mays) seedlings further to penetration of a bilayered soil consisting of loose loamy sand on top and a coarser, denser layer beneath.
Upon reaching the compacted soil in the lower layer, the elongation rate of the primary roots nearly halved and the tortuosity and deflection of the root path significantly changed in response to contact with the changing soil texture. The resulting ‘waviness’ of the root serves as a key indicator of the maize roots’ response to touch stimuli as they encounter a changing physical soil environment.
This paper is part of the Root Biology Special Issue.
Liyana Popova, Dagmar van Dusschoten, Kerstin A. Nagel, Fabio Fiorani, Barbara Mazzolai, 2016, 'Plant root tortuosity: an indicator of root path formation in soil with different composition and density', Annals of Botany, vol. 118, no. 4, pp. 685-698 http://dx.doi.org/10.1093/aob/mcw057