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

Abstract

Plants are known to exhibit a thigmomorphogenetic response to mechanical stimuli by altering their morphology and mechanical properties. Wind is widely perceived as mechanical stress and in many experiments its influence is simulated by applying mechanical perturbations. However, it is known that wind-induced effects on plants can differ and at times occur even in the opposite direction compared to those induced by mechanical perturbations. In the present study the long-term response of Arabidopsis thaliana to a constant unidirectional wind was investigated. We found that exposure to wind resulted in a positive anemotropic response and in significant alterations to Arabidopsis morphology, mechanical properties, and anatomical tissue organisation that were associated with the plant’s acclimation strategy to a windy environment. Overall, the observed response of Arabidopsis to wind differs significantly from previously reported responses of Arabidopsis to mechanical perturbations. The presented results suggest that the Arabidopsis’ response is sensitive to the type of mechanical stimulus applied, and that it is not always straightforward to simulate one type of perturbation by another.

Unidirectional versus bidirectional brushing: Simulating wind influence on Arabidopsis thaliana

“…This difference can be related to the higher total number of perturbations received by Arabidopsis plants in the study by Paul-Victor and Rowe (2011), where 80 additional brushes were made at the end of each day. In addition, Paul-Victor and Rowe (2011) started the mechanical perturbation of Arabidopsis at an earlier developmental stage, that is, at the leaf developmental stage, whereas in the present study, brushing treatment commenced from the inflorescence emergence stage, to be consistent with the previously conducted wind treatment experiments (Zhdanov et al, 2021). On the other hand, the inhibition of the stem length in the present unidirectional brushing experiment is found to be similar to the effects of exposure to constant unidirectional wind (Zhdanov et al, 2021) and periodic multidirectional wind (Bossdorf & Pigliucci, 2009) of 5 m/s, where stem length reductions of 14 and 13.2% were reported, respectively.…”

“…Mechanical perturbations are also known to affect the aboveground biomass due to its reallocation to the belowground part of the plant (Coutand et al, 2008;Kern et al, 2005). The significant decrease in Arabidopsis aboveground biomass has also been reported in the literature as a result of wind treatment (Bossdorf & Pigliucci, 2009;Zhdanov et al, 2021). However, none of the applied types of brushing treatment resulted in significant effect on the biomass in the present study, with only slight reduction observed in all experimental groups.…”

“…While no tropic response was observed in the bidirectional brushing experiment (Figure 3d,f), unidirectional brushing evoked a positive tropic response in Arabidopsis (Figure 3e,g), and young seedlings curved in the direction opposite to the direction of brushing. The observed positive thigmotropic response resembles the positive anemotropic response of Arabidopsis to a constant unidirectional wind treatment (Zhdanov et al, 2021), but without a windswept shape of the plant. Therefore, a careful selection of the type of brushing treatment allows to mimic the tropic response in Arabidopsis as in the case of exposure to unidirectional wind, although this response is thigmotropic rather than anemotropic.

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“…In our recent study (Zhdanov et al, 2021), we demonstrated that the response of the widely used model plant Arabidopsis to a constant unidirectional wind is significantly different compared with those reported as a result of brushing (Paul-Victor & Rowe, 2011) in terms of changes in plant morphology, mechanical properties and anatomical tissue composition of its primary inflorescence stem. Moreover, Arabidopsis exhibits a positive anemotropic response to this type of treatment.…”

Between Stress and Response: Function and Localization of Mechanosensitive Ca2+ Channels in Herbaceous and Perennial Plants

“…Tree acclimation to wind loads has been demonstrated not only in controlled experiments but also in a forest context [60]. Although most striking in perennials, thigmomorphogenesis has also been reported in herbaceous plants, for instance Arabidopsis [61,62] and Plantago major [63], and aquatic plants [64].…”