Poly(vinyl alcohol) cryogels as carriers of phytohormones

Introduction

In recent years, hydrogel materials have seen increasing use in agriculture, especially for combating soil erosion and enhancing plant productivity.

Poly(vinyl alcohol) cryogels are physical macroporous heterophase gels formed by freezing polymer solutions, maintaining them in a frozen state, and then thawing them. PVA cryogels can serve as carriers of various biologically active substances, such as phytohormones that influence plant growth and development.

Methods

Auxins are a group of phytohormones that play a key role in regulating plant growth and development. These compounds are universal plant growth regulators that affect cell division, elongation, morphogenesis, and the formation and growth of plant roots. In this work, poly(vinyl alcohol) cryogels were obtained using the freeze–thaw method in the presence of auxins at different concentrations: indole-3-acetic acid and indole-3-butyric acid in nonprotonated and salts forms. For the obtained samples, elastic moduli and heat resistance were estimated, the dynamics of auxin's release from the gel matrix into the aqueous environment were studied, and experiments on the biological activity of obtained materials were carried out.

Results

This study showed that poly(vinyl alcohol) cryogels formed with the described auxins additives retained their elastic and thermal properties. The release of substances into the aqueous environment from the gel matrix occurs without diffusion barriers. It was demonstrated that incorporating auxins into the polymer matrix of PVA cryogels does not lead to a change in their biological activity; specifically, rhizogenesis in plants is stimulated, leading to the formation of more roots and enhanced plant growth.

Conclusion

Thus, PVA cryogels with auxin additives represent a promising type of hydrogel that can be effectively used in agriculture to improve plants' phytoproductivity.