Magnetic resonance imaging reveals functional anatomy and biomechanics of a living dragon tree

Abstract

Magnetic resonance imaging (MRI) was used to gain in vivo insight into load-induced displacements of inner plant tissues making a non-invasive and non-destructive stress and strain analysis possible. The central aim of this study was the identification of a possible load-adapted orientation of the vascular bundles and their fibre caps as the mechanically relevant tissue in branch-stem-attachments of Dracaena marginata. The complex three-dimensional deformations that occur during mechanical loading can be analysed on the basis of quasi-three-dimensional data representations of the outer surface, the inner tissue arrangement (meristem and vascular system), and the course of single vascular bundles within the branch-stem-attachment region. In addition, deformations of vascular bundles could be quantified manually and by using digital image correlation software. This combination of qualitative and quantitative stress and strain analysis leads to an improved understanding of the functional morphology and biomechanics of D. marginata, a plant that is used as a model organism for optimizing branched technical fibre-reinforced lightweight trusses in order to increase their load bearing capacity.

Bark, the neglected tree postural motor system

“…We fully agree with Clair et al ., who state that ‘… this mechanism could be widespread in vascular plants’, and consider that continuing biomechanical and functional‐morphological research would likely lead to a much deeper understanding of mechanical processes in plants in general, and of re‐erection and other shape‐altering processes specifically. We especially encourage further research with the help of modern and noninvasive methods, such as magnetic resonance imaging, in combination with biomechanical testing (Hesse et al ., ), where functioning and adaptivity of such fibrous networks can be evaluated in vivo and over a long time span, including developmental processes.…”

Biomechanics of selected arborescent and shrubby monocotyledons

“…Finally, the technical implementation of the functional principles of such plants can be aided by finite element modelling [7]. Further studies using in vivo magnetic resonance imaging allow for revealing the internal stress–strain relationships in mechanically loaded stems of monocotyledons [50] and shall be extended to other plants.…”

A qualitative analysis of the bud ontogeny of Dracaena marginata using high-resolution magnetic resonance imaging

“…In the first step of a biomimetic approach, the morphology, anatomy and biomechanics of junctions between the branch and stem have to be analyzed to understand their form-structure-function principles 8 . These can then be abstracted and transferred into technical fiber-reinforced branchings for automotive and aerospace constructions, sporting goods and architecture 2 , 9 – 12 . In the past, the gained knowledge on the mechanical properties of branchings was, however, often based on theoretical considerations (using simulations 6 , 11 ) and two-dimensional analyses of the branching regions (by deformation analysis and anatomical evaluations of thin sections 1 , 3 , 13 – 15 ).…”