hydro-responsive curling of the resurrection plant selaginella lepidophylla
An ancient resurrection plant, a spirally arranged stem of a small ear, curled tightly into a nest-
Spherical after dehydration.
Due to its spiral leaf sequence, the older outer stems on the plant interweave together and wrap the younger inner stems that form the center of the plant.
Stem curl is a morphological mechanism that limits the light inhibition and thermal damage that plants may experience in dry environments.
Here, we study the different conformations of the outer and inner stems of S.
Dehydration caused by Lepidophylla.
The outer stem is bent into a circular loop in a relatively short drying time, while the inner stem is slowly curled into a spiral due to hydraulic action
The induced strain gradient along its length.
This arrangement simplifies the tight packaging of plants during drying and the rapid opening after dehydration.
Insights gained from this work reveal Hydropower
The movement of response in plants may help to develop an unfolded structure that responds to environmental stimuli with significant shape changes.
Get mature dehydration from Air Canada in New Brunswick, Canada.
Plants remain dry under laboratory conditions (
The relative humidity is 25 °C, 50%). Time-
Shoot invalid video using Logitech C920 HD Pro Webcam (
Zeiss optical 1080 p)
And video speed time
Delay Studio software (Candylabs).
Allow plants to replenish water 24 hours a day, with a single inner stem (
Choose from 1/4 to 1/3 along the spiral to match the length of the mature stem)
Outer stem (
Choose from about 3/4 along the spiral)
Cut the length of about 5 cm from the rootstem interface. Microphylls (leaves)
Cut off, the stem is fixed in a metal clip fixed to the bottom of a square petri dish.
Then allow stem air-
Dry for about 6 hours during which time changes in their curvature are captured by time
Shoot at 1 minute frame rate.
The stems are taken from three different plants.
A total of 4 internal and 4 external stems were tested and similar curl/no curl patterns were shown.
The model proposed in this paper is based on a single representative sample from the internal and external sample pools.
The rehydrated stem is stripped out of the microleaf and fixed at both ends through the clip, using the ADMET MicroEP machine to measure the dry-induced pull force. Stems (
8 inside and 8 outside)
Then allowed to air-
Dry, calculate the change of load over time every five minutes, for a total of 220 minutes.
Use Mettler AJ100 analytical balance to calculate the weight change between stem heavy water and dehydration state.
The stem rehydrate overnight, and the excess water expands from the surface of the stem.
Place separate external and internal stems on the balance and allow air-
Dry 220 minutes and 350 minutes respectively.
The percentage of weight loss is calculated based on the weight of the stem in a fully hydrated state, such as * = 100 × (− )/.
Chlorhexidine blue O (TBO)
It is used for the detection of wood fat and fruit. Spurr\'s resin-
Embedded slices are stained with 0. 05% TBO in 0. 01 cucm po buffer (pH 5. 7)
For the 10 s on the hot plate (60°C)
Rinse with deionised water.
The prepared sections were observed with a strong light microscope.
The wood was confirmed and tested with alkaline magenta. Paraffin-
Embedded slice dyeing 0.
0001% alkaline magenta (in 70% ethanol)
5 minutes, wash in 70% ethanol for 2 minutes and rinse briefly in deionised water.
The sample is installed in 50% glycerin and observed with TX2 (RFP filter set).
The prepared sections were observed using Leica DM6000B fluorescence microscope. Finite element (FE)
The simplified outer and inner stem models were simulated using the commercial software package ansys (
USA, RI, Providence, rising Mills). The hydro-
Drive strain is simulated with thermal expansion, where temperature represents moisture content. The rod-
Modeled as an unscalable elastic beam like a stem and discrete with a mixed secondary beam unit (B32H).
Curl is induced by introducing a thermal strain gradient in the beam section.
Spatial variation of water
The analytical field derived from the curvature distribution is used to introduce the driving capability along the length of the stem into the model.
Discrete FE double-layer model with elastic plane stress quadratic element (CPS6).
The stem is caught at the bottom of it.
Geometric nonlinear is considered, but since
The contact of the stem was ignored.
The curl of the stem is simulated by applying negative thermal strain on the active layer.
The grid size sensitivity analysis was carried out and based on a grid of about 7 elements along the stem thickness (~5000 elements)was chosen.
This selection results in fairly consistent results within the range of parameters considered in this work, and enables us to successfully extract curvature values at a later stage
Processing phase.
More information is provided on the FE model of the double-layer stem.