TRANSPORT OF LIGNOHUMATE THROUGH PLANT CUTICLE - METHOD OF DIFFUSION COUPLE WITH BARRIER ON THE INTERFACE

Agarose hydrogel was used as the transport medium for the investigation of the diffusion of lignohumate through plant cuticle. The cuticles were isolated from Prunus laurocerasus by two different methods: chemical and enzymatic. At first, the diffusion coefficient of lignohumate in agarose hydrogel was determined by means of the technique of diffusion couple: the donor part was enriched by lignohumate with homogeneous distribution on its whole volume and connected with the "pure" acceptor part without lignohumate. The diffusion coefficient was calculated on the basis of time development of diffusion flux through the interface. After that, the cuticle was placed into interface between donor and acceptor parts and the barrier ability of cuticles were characterized by the decrease in diffusion flux and the change of the concentration of lignohumate at the interface between donor and acceptor hydrogels. The transport through chemically and enzymatically cuticles as well as the abaxial (stomatous) and adaxial (astomatous) cuticles was investigated. Diffusion characteristics were determined, compared and discussed.