A new perspective on mechanical characterisation of Arabidopsis stems through vibration tests

Abstract

The mechanical properties of plants are important for understanding plant biomechanics and for breeding new plants that can survive in challenging environments. Thus, accurate and reliable methods are required for the determination of mechanical properties such as stiffness and Young's modulus of elasticity. Much attention has been paid to the application of static methods to plants, while dynamic methods have received considerably less attention. In the present study, a dynamic forced vibration method for mechanical characterisation of Arabidopsis inflorescence stems was developed and validated against the conventional three-point bending test. Compared to dynamic tests based on free vibration, the current method allows to determine simultaneously more than one natural frequency, thus increasing the overall accuracy of the results. In addition, this method can be applied to the top parts of the stems that are more flexible, and where application of the three-point bending test is often limited. To demonstrate one of the potential applications of this method, it was applied to evaluate the influence of turgor pressure on the mechanical properties of Arabidopsis stems. Overall, the new dynamic testing approach has been shown to provide reliable data for the local mechanical properties along the Arabidopsis inflorescence stem.

Wind-evoked anemotropism affects the morphology and mechanical properties of Arabidopsis

“…Mechanical characterisation of Arabidopsis primary inflorescence stems was conducted using the dynamic forced vibration method (Zhdanov et al, 2020). In this method, the mechanical properties of the tested stem segments are estimated through their multiple resonant frequencies (݂ ) using Euler-Bernoulli beam theory (Blevins, 1979):…”

“…For the bottom part of the stem the determined mechanical proprieties were averaged over the first three natural frequencies while for the top part the first four natural frequencies were used. The multiple resonant frequency method was previously validated against a standard three-point bending tests (Zhdanov et al, 2020). The tests were performed immediately after the cutting of each segment to avoid changes in the mechanical properties of the stem segments due to dehydration and decrease in turgor pressure.…”

Unidirectional versus bidirectional brushing: Simulating wind influence on Arabidopsis thaliana

“…Mechanical characterisation of the primary inflorescence stems of perturbed and control plants was carried out using the dynamic forced vibration method (Zhdanov et al, 2020 ) for 10 plants from each group. Two segments of the primary inflorescence stem were characterised.…”

“…The stem segments were tested as clamped–clamped beams, and up to four vibration modes were considered with the corresponding values of from Blevins ( 1979 ; , , and ). The detailed testing procedure can be found in Zhdanov et al ( 2020 ). The product of is known as bending rigidity and characterises the ability of the structure to resist bending.…”

Biochemical and Physiological Responses of Arabidopsis thaliana Leaves to Moderate Mechanical Stimulation

“…The studies conducted so far included different types of mechanical stimuli, however they were rarely quantified, making it difficult to compare data from different studies as pointed out by Coutand [65]. In most cases, mechanical stimuli have been quantified as the number of rubbing [22], touching [21], bending [66], and brushing treatments [15], and these studies have focused mainly on the effects on growth, morphological, and developmental changes [18,67]. Unlike these long-term effects, mechanical stimulation triggers numerous physiological and biochemical changes that can be detected in a much shorter time than phenotypic modifications.…”