Use of Emulsion-Templated, Highly Porous Polyelectrolytes for In Vitro Germination of Chickpea Embryos: a New Substrate for Soilless Cultivation

Abstract

The application of highly porous and 3D interconnected microcellular polyelectrolyte polyHIPE (PE-PH) monoliths based on (3-acrylamidopropyl)-trimethylammonium chloride as soilless cultivation substrates for in vitro embryo culture is discussed. The embryo axes isolated from chickpea seeds are inoculated onto the surface of the monoliths and allowed to germinate. Germination study show that the newly disclosed PE-PH substrate performs much better than the conventionally used agar as the germination percentage, shoot and root length, fresh and dry weight as well as the number of leaves are enhanced. The PE-PHs exhibit a higher absorption capacity of the plant growth medium, that is, 36 g·g –1 compared to agar, that is, 20 g·g –1 , and also survive autoclaving conditions without failing. The key advantage over standard agar substrates is that they can be reused several times and also without prior sterilization. These results suggest that PE-PHs with exceptional absorption/retention properties and robustness have great potential as soilless substrates for in vitro plant cultivation.

Macroporous hydrogels for soil water retention in arid and semi-arid regions

“…For example, templated macroporous hydrogels can act as a seed coating material for agriculture applications to ensure good hydration and increase germination. 45 The seed can be coated by the template and then crosslinked, or the powdered foam can be planted with the seeds to ensure moisture capture. The use of HIPE templating improves water absorption and reduction in cost.…”

Synthesis and Applications of Elastomeric Polymerized High Internal Phase Emulsions (PolyHIPEs)

“…Aqueous Absorbents and Ionic Molecule Capture. Elastic PolyHIPEs consisting of highly hydrophilic or charged polymer networks have been prepared that have properties including superswelling in aqueous environments and have been used in applications including reinforced hydrogels, 47 soil-free plant growth, 48 and aqueous absorb- ents. 49 For example, Kovacǐčand co-workers 48 prepared a polyelectrolyte polyHIPE from (3-acrylamidopropyl)-trimethylammonium chloride (AMPTMA) that showed water uptake as high as ∼35 g/g that could support growth of chickpea roots through the media (Figure 7).…”

“…Elastic PolyHIPEs consisting of highly hydrophilic or charged polymer networks have been prepared that have properties including superswelling in aqueous environments and have been used in applications including reinforced hydrogels, 47 soil-free plant growth, 48 and aqueous absorbents. 49 For example, Kovačič and co-workers 48 prepared a polyelectrolyte polyHIPE from (3-acrylamidopropyl)-trimethylammonium chloride (AMPTMA) that showed water uptake as high as ∼35 g/g that could support growth of chickpea roots through the media ( Figure 7 ). Similarly, Silverstein and Kovačič 50 prepared a series of polyelectrolyte polyHIPEs from 2-acrylamido-2-methyl-propanesulfonic acid (AMPS) and N , N ′-methylenebis(acrylamide) that showed a water uptake capacity as high as ∼340 g/g, which is higher than that of the commercial absorbent (SAP powder) used in diapers.…”

“…(b) SEM image of the porous structure of the dried polyelectrolyte polyHIPE (left) and digital images of the polyHIPE supporting growth of a chickpea plant compared to an agar control. Modified with permission from ref ( 48 ). Copyright 2022 American Chemical Society.…”

Porous superabsorbent composites prepared from aqueous foam template and application evaluation

“…However, there has been limited research on improving the water absorption rate, with most studies concentrating on the development of porous materials to achieve rapid water absorption. Common methods for producing porous materials include hydrothermal synthesis, 6 freeze-drying, 7 the emulsion template method 8,9 and the foam template method. 10 Among these, the foam template method stands out as one of the most frequently used, effective, and environmentally friendly techniques for generating porous materials.…”